Apex Class Permissions for Administrators

The following table displays the permissions required by administrators for Apex classes:

Apex Class	Enabled
AP	TRUE
AbstractAgreementTermExActionController	TRUE
AbstractApprovalEmailController	TRUE
AbstractApprovalEngineProcessTerm	TRUE
AbstractApprovalsTest	TRUE
AbstractQueryCallback	TRUE
AbstractSObjectApprovals2	TRUE
AdhocApprovalGroup	TRUE
AdhocApprovalProcess	TRUE
AdhocApprovalProcessFactory	TRUE
AdhocApprovalTestSupport	TRUE
AdhocApproverFactory	TRUE
AdhocProcessRuntimeControllerTest	TRUE
AgreementApprovalEmailController	TRUE
AgreementApprovalSummaryController	TRUE
AgreementLIApprovalEmailControllerTest	TRUE
AgreementLItemApprovalSummaryController	TRUE
AgreementTEApprovalEmailControllerTest	TRUE
AgreementTermExAddTest	TRUE
AgreementTermExApprovalSummaryController	TRUE
AgreementTermExApprovalsController	TRUE
AgreementTermExCancelController	TRUE
AgreementTermExEditController	TRUE
AgreementTermExHistoryController	TRUE
AgreementTermExPreviewController	TRUE
AgreementTermExSubmitController	TRUE
AgreementTermExWrapper	TRUE
ApprovalActionTest2	TRUE
ApprovalChildProcess	TRUE
ApprovalConfigTest	TRUE
ApprovalContext	TRUE
ApprovalContextCancelTest	TRUE
ApprovalContextPreviewController	TRUE
ApprovalContextSubmitController	TRUE
ApprovalCustomConfig	TRUE
ApprovalData	TRUE
ApprovalDataTransferAgent	TRUE
ApprovalEmailHandler	TRUE
ApprovalEngine2	TRUE
ApprovalEngineConsolidationSupport	TRUE
ApprovalEnginePrescanSupport	TRUE
ApprovalEngineProcessAgreementTermEx	TRUE
ApprovalEngineProcessContextQueueable	TRUE
ApprovalEngineProcessRequest	TRUE
ApprovalEngineStepSupport	TRUE
ApprovalEngineSupport	TRUE
ApprovalEngineTestATESupport	TRUE
ApprovalEngineTestAgmtSupport	TRUE
ApprovalEngineTestOpptySupport	TRUE
ApprovalHistoryControllerTest	TRUE
ApprovalMatrixAssigneeSupport	TRUE
ApprovalMatrixGenerateTest	TRUE
ApprovalMatrixResolver	TRUE
ApprovalMatrixViewController	TRUE
ApprovalPolicySupport	TRUE
ApprovalProcessDefnController	TRUE
ApprovalProcessDefnListController	TRUE
ApprovalProcessFactory	TRUE
ApprovalProcessFinalActionController	TRUE
ApprovalProcessInitialActionController	TRUE
ApprovalProcessInstance	TRUE
ApprovalProcessQryHelper	TRUE
ApprovalProcessResolverTest	TRUE
ApprovalProcessStepControllerTest	TRUE
ApprovalProcessTest2	TRUE
ApprovalRequestAttachmentController	TRUE
ApprovalRequestEscalateController	TRUE
ApprovalRequestQryHelper	TRUE
ApprovalRequestReassignController2	TRUE
ApprovalRequestSupport	TRUE
ApprovalRequestsListTest	TRUE
ApprovalRequiredCheckTest	TRUE
ApprovalRuleAssignee	TRUE
ApprovalRuleController	TRUE
ApprovalRuleCriteriaEditController	TRUE
ApprovalRuleDimension	TRUE
ApprovalRuleDimensionControllerTest	TRUE
ApprovalRuleDimensionSupport	TRUE
ApprovalRuleEntryController	TRUE
ApprovalRuleEntryFactory	TRUE
ApprovalRuleSupport	TRUE
ApprovalStatusUpdateBatchJob	TRUE
ApprovalSubprocess	TRUE
ApprovalSummaryLaunchController	TRUE
ApprovalSystemException	TRUE
ApprovalUserSupportTest	TRUE
ApprovalsController	TRUE
ApprovalsWebService	TRUE
ApprovalsWebServiceTest	TRUE
AssigneeCacheSupport	TRUE
AsyncActionSupport	TRUE
AsyncJobSupport	TRUE
AttachmentWrapper	TRUE
BackupAdminSupportTest	TRUE
BackupApproverActionTest	TRUE
BackupApproverSupport	TRUE
BackupUserSearchController	TRUE
BatchPreviewApprovals	TRUE
BulkActionRequest	TRUE
ChildSOSupport	TRUE
ClauseApprovalsWebServiceTest	TRUE
ContextApprovalEmailControllerTest	TRUE
CriteriaCacheTest	TRUE
CurrencySupportTest	TRUE
CustomAssigneeInfoTest	TRUE
CustomClass	TRUE
CustomSOSupport	TRUE
DashboardSupportTest	TRUE
ESAPISupport	TRUE
EmailSupport	TRUE
EmailTemplateFactory	TRUE
EmailTemplateTest	TRUE
EscalationReminderEmailController	TRUE
EscalationSupport	TRUE
ExprSupport	TRUE
FieldMetadata	TRUE
FileSupportTest	TRUE
FormulaFieldController	TRUE
FormulaFieldFactory	TRUE
IApprovalEngine	TRUE
InstanceUrlController	TRUE
ManagedObject	TRUE
ManagedObjectTest	TRUE
MyApprovalsController	TRUE
MyApprovalsEmailController	TRUE
MyApprovalsLaunchController	TRUE
NextLevelApproverController	TRUE
NullObject	TRUE
ObjectValue	TRUE
OneOrMoreItemsFailedException	TRUE
OpportunityApprovalSummaryTest	TRUE
OpportunityPartnersListTest	TRUE
OpportunityProductsListTest	TRUE
OpptyApprovalEmailControllerTest	TRUE
PostInstallBatchApprovalRequests	TRUE
PostInstallBatchCopyProcessId	TRUE
PostInstallScript	TRUE
PreviewSubmitApprovalsController	TRUE
Property	TRUE
QuerySpecFactory	TRUE
ReassignUserSearchTest	TRUE
ReminderInstanceSupport	TRUE
ReminderJobTest	TRUE
ReminderTest	TRUE
RuntimeContext	TRUE
SOQLSupport	TRUE
SObjectApprovalContextParam	TRUE
SObjectApprovals2SubmitController	TRUE
SObjectApprovals2Test	TRUE
SObjectApprovalsController2	TRUE
SObjectApprovalsSupport	TRUE
SObjectConstants	TRUE
SObjectMetadata	TRUE
SObjectSupport	TRUE
SearchFilter	TRUE
SearchFilterControllerTest	TRUE
SearchFilterDetailControllerTest	TRUE
SubmissionComments	TRUE
SystemUtil	TRUE
TaskConstants	TRUE
TaskSupport	TRUE
TermExApprovalCloneController	TRUE
TermExApprovalController	TRUE
TermExApprovalFactory	TRUE
TermExSupport	TRUE
TransferInflightRequests	TRUE
UIAbstractSearchController	TRUE
UIAssigneeController	TRUE
UIDataTableController	TRUE
UIDependsOnControllerTest	TRUE
UIDisplayFieldNamesControllerTest	TRUE
UIPageConfig	TRUE
UIPageControllerBase	TRUE
UIPageSupport	TRUE
UIReapprovalFilterControllerTest	TRUE
UISearchEmailTemplateController	TRUE
UISearchFilterControllerTest	TRUE
UISearchRoleController	TRUE
UISearchUserController	TRUE

For information on setting Apex class permissions, refer to this Salesforce article.