Symptom
Occasionally, while using NWBC, a .NET exception occurs and the following error message is displayed:
Invisible or disabled control cannot be activated.
This is related to a situation in the .NET 3.0 runtime, which cannot be resolved. The coding of NWBC has been enhanced to reduce the number of occurrences to a minimum, but they can never be completely eliminated.
Solution
The only way to resolve this situation is to install the latest .NET runtime, at least install .NET 3.5.