{"type":"error.SuiteScriptError","name":"RCRD_DSNT_EXIST","message":"That record does not exist.","stack":["Error\n at Object.<anonymous> (/SuiteBundles/Bundle 364000/src/adapter/fam_adapter_record.js5523)\n at Object.customizeColumns (/SuiteBundles/Bundle 364000/src/su/fam_su_manageassetproposal.js45320)\n at Object.onRequest (/SuiteBundles/Bundle 364000/src/su/fam_su_manageassetproposal.js5314)"],"cause":{"type":"internal error","code":"RCRD_DSNT_EXIST","details":"That record does not exist.","userEvent":null,"stackTrace":["Error\n at Object.<anonymous> (/SuiteBundles/Bundle 364000/src/adapter/fam_adapter_record.js5523)\n at Object.customizeColumns (/SuiteBundles/Bundle 364000/src/su/fam_su_manageassetproposal.js45320)\n at Object.onRequest (/SuiteBundles/Bundle 364000/src/su/fam_su_manageassetproposal.js5314)"],"notifyOff":false},"id":"0","notifyOff":false,"userFacing":true}

Are you sure the bundle installed successfully? That almost makes me wonder if it didn't install the proposal record properly. If you're in a Sandbox, I might wipe it out and reinstall, otherwise I'd probably file a ticket.