Participants who have received any other investigational agents within the weeks prior to enrollment; concurrent radiation therapy is not permitted, except palliative (limited-field) radiation therapy, if all of the following criteria are met:\r\n* Repeat imaging demonstrates no new sites of bone metastases\r\n* The lesion being considered for palliative radiation is not a target lesion Patients may not have had any prior systemic treatment for this malignancy (for example chemotherapy or somatostatin analogues); prior palliative radiation is permitted but radiated lesions may not be used for measurement Subjects may receive palliative radiotherapy for symptomatic metastases prior to enrollment provided that there is at least one other non-irradiated lesion amenable to LCT at the time of enrollment. Prior palliative radiation treatment for metastatic disease to be treated on the protocol (including radiopharmaceuticals) Impending need for palliative RT or surgery for pathological fractures and/or for medullary compression within four weeks prior to randomization. The last dose of prior systemic therapy (e.g. chemotherapy, targeted therapy etc) or radiation therapy (with the exception of palliative radiotherapy) was received less than days prior to the first day of treatment Patients must have failed prior radiation therapy and must have an interval of greater than or equal to days from the completion of radiation therapy to study entry; Note: patients with an indication for craniospinal radiotherapy (i.e., extensive leptomeningeal disease) but have refused palliative craniospinal radiotherapy are eligible Concurrent anticancer treatment within days before the start of trial treatment (e.g., cytoreductive therapy, radiotherapy [with the exception of palliative bone directed radiotherapy]; immune therapy, or cytokine therapy, except for erythropoietin. Palliative radiotherapy within days before initiation of study treatment Prior palliative radiation must have been completed at least weeks prior to study entry Participants who received prior non-central nervous system (CNS) directed palliative radiation therapy within days of the date of study entry Palliative radiation therapy may have been received but not within the days prior to study treatment Concurrent use of hypoglycemic agents or any systemic therapy for melanoma; palliative limited-field radiation therapy will be allowed Completed palliative radiotherapy within days of the first dose of study drug. Radiotherapy within weeks prior to therapy except palliative radiation to target organs other than primary tumor may be allowed up to weeks prior to registration Radiation therapy (palliative setting is allowed.): ? weeks Anticancer treatment within days before the start of trial treatment (e.g., cytoreductive therapy, radiotherapy [with the exception of palliative radiotherapy delivered in a normal organ-sparing technique], immune therapy, or cytokine therapy). Concurrent therapy considered investigational\r\n* NOTE: patients must not be planning to receive any radiation therapy (except localized radiation for palliative care that must be completed prior to starting cycle , day ) Lesion that is amenable to palliative radiotherapy At least weeks after any prior palliative radiation (e.g. to focal metastatic lesion such as bone metastases) and recovery to =< grade treatment-related toxicity The last dose of previous therapy must have occurred at least weeks prior to the start of study therapy; palliative radiotherapy is allowed up to weeks before the first LMB- infusion Anticancer treatment within days before the start of trial treatment (e.g., cytoreductive therapy, radiotherapy [with the exception of palliative radiotherapy delivered in a normal organ-sparing technique], immune therapy, or cytokine therapy). Radiotherapy: ? weeks (patients who receive palliative radiation for nontarget tumour lesions need not be subjected to this washout period and can be enrolled immediately) Prior palliative radiotherapy to non-central nervous system (CNS) lesions must have been completed at least weeks prior to treatment; subjects with symptomatic tumor lesions at baseline that may require palliative radiotherapy within weeks of first treatment are strongly encouraged to receive palliative radiotherapy prior to treatment Patients who had undergone any palliative radiation within weeks of study enrollment Planned palliative procedures for alleviation of bone pain such as radiation therapy or surgery Subjects who had major surgery or radiation therapy within weeks of the first dose of study drug, except for palliative radiotherapy to a limited field, such as for the treatment of bone pain or a focally painful tumor mass. Patient must not be a candidate for curative surgical or radiation therapy\r\n* NOTE: Palliative radiotherapy is permitted If palliative radiotherapy administered, completion of palliative radiation therapy must be >= weeks prior to cycle day of protocol therapy At least one tumor for which palliative RT is considered appropriate standard therapy (cohort ); or, at least one tumor for which palliative ablation is considered appropriate standard therapy (cohort ) Prior palliative radiotherapy must have been completed at least weeks prior to registration; subjects with symptomatic tumor lesions at baseline that may require palliative radiotherapy within weeks of randomization are strongly encouraged to receive palliative radiotherapy prior to randomization Subjects requiring palliative radiation therapy at presentation Palliative (limited-field) radiation therapy is permitted, if all of the following criteria are met:\r\n* Repeat imaging demonstrates no new sites of bone metastases\r\n* The lesion being considered for palliative radiation is not a target lesion No planned palliative procedures for alleviation of bone pain such as radiation therapy or surgery Participants who have had chemotherapy other than R-EPOCH or R-CHOP, or radiotherapy other than palliative radiation for medical emergencies (like cord compression), within the last weeks Concurrent therapy considered to be investigational; NOTE: patients must not be planning to receive any radiation therapy (except localized radiation for palliative care that must be completed prior to starting cycle , day ) Emergent need for palliative radiation Palliative surgery and/or radiation treatment within days prior to course day (CD) \r\n* Localized therapy of non-target lesions is allowed The last dose of previous therapy must have occurred at least weeks prior to the start of study therapy; palliative radiotherapy is allowed up to weeks before the first LMB- infusion Need for urgent palliative intervention (e.g., impending herniation) Prior systemic therapy, radiation therapy, or surgery within the days of starting study treatment; palliative radiotherapy to a limited filed or palliative cryoablation is allowed after consultation with the principal investigator, at any time during the study participation including screening Palliative radiotherapy for bone metastasis/lesion within weeks prior to the initiation of study treatment; All patients must have completed any prior chemotherapy, targeted therapy, radiotherapy (unless palliative doses which must be discussed with study principal investigator), surgery, anti-angiogenic therapy or interferon >= days before study entry Patients must have histologically or cytologically confirmed advanced, incurable cancers of the esophagus, liver, stomach, small bowel, pancreas, bile duct, colon or rectum and be eligible to receive chest, abdominal and/or pelvic radiation therapy (RT) for palliation; documentation of this is required in physician note; concomitant systemic therapy is not allowed during administration of palliative RT; palliative RT can be considered for advanced primary tumors or metastatic disease as above Radiotherapy within weeks prior to enrollment, except as follows:\r\n* Palliative radiation to target organs other than chest may be allowed up to weeks prior to enrollment, and\r\n* Single dose palliative treatment for symptomatic metastasis outside above allowance to be discussed with sponsor-investigator prior to enrolling Patient must be weeks off any palliative radiation or craniospinal radiation Palliative surgery and/or radiation treatment < days prior to date of randomization. Metastatic cancer requiring palliative radiation therapy Palliative radiation is allowed to sites that will not be used to measure response during this study Any concurrent therapy for cancer, radiation, or surgery within weeks, except for minor palliative intent (this is to be discussed with sponsor) Patients must have at least one lesion not previously irradiated (and not within a previously irradiated field) for which palliative radiation to the abdomen and/or pelvis is potentially indicated and could be safely delivered at the radiation doses specified in this protocol; this lesion must not be within the central nervous system (CNS) (brain or spinal cord), bone or liver, and must not require urgent or emergent palliative radiation given the timing of radiation specified on this protocol; furthermore, this lesion must be located in the abdomen or pelvis and measure at least cm (minimum dimension) and no greater than cm (maximum dimension); palliative radiotherapy would entail involved-field radiotherapy to a single lesion or region to encompass gross disease; whole-abdomen radiotherapy would not be permitted; patients who received prior vaginal brachytherapy would be permitted to receive palliative pelvic radiation; in the expansion cohort at the maximum tolerated dose (MTD), this lesion must not be the only measurable lesion so that it is possible to determine the response rate outside of the radiation treatment field Palliative surgery and/or radiation treatment less than weeks prior to initiation of study treatment. Prior anti-cancer therapy or radiation therapy within weeks prior to enrolment. Palliative radiotherapy to metastatic lesion(s) permitted providing that it has been completed at least days prior to enrolment and no significant toxicity are expected. Prior radiotherapy within weeks of study treatment. A -week washout period is permitted for palliative radiation to non-CNS disease with medical monitor approval. Localized palliative radiation therapy is allowed for symptom management if completed >= days prior to randomization Any radiotherapy within weeks except palliative stereotactic body radiation therapy (SBRT) within weeks Radiation therapy in the last days; palliative radiation to a localized area without residual toxicity requires a washout of greater than days Palliative radiotherapy (? fractions) within weeks prior to Screening Patients must be candidates for palliative radiation Palliative radiotherapy for bone metastases < weeks prior to cycle , day Prior palliative radiation therapy to bony metastases is allowed; there should be a minimum of days between the end of radiation treatment and start of study treatment Subjects who received palliative radiotherapy ? weeks of study drug initiation. discontinued previous localized radiotherapy for palliative purposes or for lytic lesions at risk of fracture at least weeks prior to randomization and recovered from the acute effects of therapy Prior palliative radiation therapy to bony metastases will be allowed; there should be minimum of days between the end of radiation treatment and start of study treatment Palliative radiation therapy to bony metastases = . cm) outside of the planned palliative radiation therapy field Women with planned treatment of palliative radiotherapy Palliative radiation to bony metastases within weeks prior to initiation of ipatasertib Patients may receive palliative radiation therapy before or during treatment on protocol, provided that there is measurable or evaluable disease out of the radiation field; patients may receive palliative radiation therapy, if needed, hours after last dose of investigational drug; in addition patients may be enrolled on trial seven days following palliative radiation; we will closely monitor for the appearance of radiation recall reactions; hormonal therapy may continue in patients who have been on such treatment for three months or longer Radiation therapy within the last weeks prior to randomization(with exception of palliative radiotherapy) Prior palliative radiotherapy to non-central nervous system (CNS) lesions must have been completed at least weeks prior to enrollment; subjects with symptomatic tumor lesions at baseline that may require palliative radiotherapy within weeks of enrollment are strongly encouraged to receive palliative radiotherapy prior to enrollment Palliative radiotherapy is allowed up to weeks before the first RO infusion; palliative Gy radiotherapy is allowed during therapy. Patients cannot receive concomitant radiation therapy at enrollment; while on protocol limited palliative radiotherapy extending over a small bone marrow field (%) is allowed Prior palliative or curative radiotherapy must be completed at least days prior to randomization Localised palliative radiotherapy Prior chemotherapy must be > months before screening Palliative radiation, including whole brain radiation therapy (WBRT), is allowed prior to enrollment as long as it is completed > weeks from initiation of study treatment, and provided patient has recovered from treatment toxicities to =< grade Palliative radiation to bone metastases within weeks prior to Day Palliative radiotherapy within weeks prior to first dose of study-drug treatment in Cycle An immediate need for palliative radiotherapy or systemic corticosteroid therapy. Palliative surgery or radiotherapy. Received palliative/focal radiotherapy within weeks of first dose of study treatment. Prior radiation therapy completed < weeks or single fraction of palliative radiotherapy < days prior to first dose of KPT- (selinexor) Palliative surgery and/or radiation treatment within days prior to date of randomization. Palliative radiation therapy to metastatic sites of disease < weeks prior to study day . within weeks prior to the first dose of KTN in the case of palliative radiation therapy. Palliative surgery and/or radiation treatment less than weeks to randomization. Palliative radiation within weeks prior to Day . An immediate need for palliative radiotherapy or systemic corticosteroid therapy Therapeutic or palliative radiation therapy within days of starting treatment Planned palliative procedures for alleviation of bone pain such as radiation therapy or surgery Patient is receiving concurrent radiation therapy to treat primary disease with curative intent. (Note that palliative radiotherapy is allowed as long as there is no evidence of progressive disease.) Received local palliative radiation therapy < days prior to the first dose of study medication Palliative radiotherapy is not permitted throughout the study period; No concomitant anti-cancer chemotherapy or other systemic drugs; palliative radiation therapy will be allowed as long as the patient meets all other eligibility criteria Therapeutic or palliative radiation therapy within weeks prior to enrollment The participant has completed prior chemotherapy and/or radiotherapy with curative intent at least weeks prior to the administration of the first dose of study therapy. Participants that have received palliative radiation therapy to bony metastases prior to the first dose of study medication are eligible Prior systemic therapy, radiation therapy, or surgery within days of starting study treatment; palliative radiotherapy to a limited field or palliative cryoablation is allowed after consultation with the principle Investigator, at any time during the study participation including screening Palliative radiation treatment (e.g., pain control, bony lesions at risk of fracture) completed =< weeks of starting study treatment; patient will be eligible if palliative radiotherapy is completed > weeks from the start of study treatment and has recovered from radiotherapy toxicities All patients must have completed any prior chemotherapy, targeted therapy, radiotherapy (unless palliative doses which must be discussed with study principal investigator), and surgery, >= days before study entry Undergoing only palliative (not curative) radiation treatment Patients already receiving palliative care PATIENT EXCLUSION: Palliative performance scale rating < Palliative surgery and/or radiation treatment within days prior to date of screening visit. New systemic therapy for subjects cancer (palliative radiation therapy is allowed). The treatment with agents administered during previous studies which was stopped and then restarted during this study does not represent new treatment. Patients already receiving palliative care (Physician participation) a palliative medicine specialist Palliative Performance Scale (PPS) of or higher at recruitment Patient is planned to receive hypofractionated palliative radiation =< fractions Previous radiotherapy or palliative surgery to the painful site that is planned for treatment Receiving palliative radiation therapy At the time of day of the study, patients must have completed chemotherapy, targeted therapy, investigational therapy, other immunotherapy, radiation therapy or major surgery (requiring general anesthesia) at least days before administration of the first dose of nivolumab; patients undergoing minor surgical procedures and biopsies that do not require general anesthesia may begin receiving study therapy if sufficiently recovered as determined by the treating investigator; patients may have received prior focal radiotherapy for palliation of an isolated site of disease, which must be completed at least days prior to day of the study; palliative (limited-field) radiation therapy is permitted during treatment with study drug(s), if all of the following criteria are met: \r\n* The lesion being considered for palliative radiation is not a target lesion\r\n* Radiation treatment is administered weeks or greater after their first dose of study drug Radiation (except planned or ongoing palliative radiation to bone outside of the region of measurable disease) =< weeks prior to study drug administration date Treatment with palliative or pre-operative radiation Patients who receive RT or CRT with palliative intent Patient receiving palliative radiation therapy (defined as less than Gy) Prior radiotherapy within weeks of study treatment. A -week washout period is permitted for palliative radiation to non- central nervous system (CNS) disease with medical monitor approval. > week since palliative RT Patients treated with radiation for palliative intent Expected to require other cancer therapy while on study with the exception of local palliative radiation treatment to the site of bone and other metastasis. Palliative radiotherapy within weeks prior to first dose of study drug treatment in Cycle Expected to require other cancer therapy while on study with the exception of local palliative radiation treatment.