| EmptyContextIssue | Indicates a placeholder returned an empty context, though it was required. |
| IncompatibleContextIssue | Occurs when a first position level command does not accept the current contexts type. |
| IncompatibleLevelsIssue | Occurs when a level command does not accept any of the context types which the preceding level command outputs. |
| InvalidCommandTypeIssue | Occurs when a level command accepts no context but is not positioned at the beginning of its placeholder. |
| InvalidExpansionContextIssue | Indicates a level was given an expansion context it isn't compatible with. |
| InvalidLevelPositionIssue | Occurs when a level command accepts no context but is not positioned at the beginning of its placeholder. |
| UnknownCommandIssue | Occurs when a level command is used that is not registered in the placeholder settings. |
| UnresolvedClassIssue | Occurs when a level command's parameter references an unresolved class. |
| UnresolvedObjTypeIssue | Occurs when a level command's parameter references an unresolved object type. |
| UnresolvedPropertyDefIssue | Occurs when a level command's parameter references an unresolved property def. |
| UnresolvedStateIssue | Occurs when a level command's parameter references an unresolved state. |
| ValueListsNotSupportedIssue | Occurs when a level parameter resolves to a value list when only real object types are supported. |