If only Visual Studio would open in the same state that it was closed..
Excluded DLLs in set up packages seem to re-include themselves, projects in solutions disappear, and today an ArcObects command seemed to have disappeared.
All had previously been running without problems in debugging mode, opening ArcMap and then stopping at various breakpoints. However today no breakpoints were hit. Not even on the OnCreate or New functions of the BaseCommand. The button in ArcMap had disappeared. Adding it manually from the .tlb gave the “No New Objects Added” message.
Some time later after much blood, sweat, (and possibly tears), I delved into the registry. I searched for the class ID in key values and names. The class ID can be found in the class code file of the tool:
Public ConstClassId As String = “480d624c-3d4c-4210-ae11-0c775dddc35d”
Then I took the rather risky step of deleting all these keys. If anyone does the same I’d recommend making a backup of the registry first – not that I did myself..
Anyway I think the class must have been registered twice, or there was an error in the registry, as the next time I started the project with debugging everything had started working again =)