When drilling down to view details on a task instance there was a red X error in the console,
Unhandled error Error in the application. [Altiris.TaskManagement.Exceptions.ItemVersionNotFoundException @ Altiris.TaskManagement] at Altiris.TaskManagement.ItemVersionCache.GetClassGuidForVersionOrItem(Guid versionOrItemGuid) at Altiris.TaskManagement.ItemVersionCache.LoadVersion(ItemVersionGuid itemVersionGuid) at Altiris.TaskManagement.ItemVersionCache.InternalGetItemVersionFromDatabase(O bject context) at Altiris.DotNetLib.Collections.SafeObjectCache.GetObject(Type objectType, Guid objectGuid, AltirisGetObjectDelegate delegateIfNotExist, Object delegateContextData)
Known defect. This issue will happen on task instances for jobs that have had tasks removed from the job and the task deleted.
This issue is fixed as a pointfix for 7.5 sp1 HF5 (attached to KB) and is fixed in 7.6 HF6.