Error 16884 item designation is already used in Different ID
I have had the same issue in an 800xA System 6.0.3. When opening the project and checking the code on some client PCs we encountered this issue.
The code from all tabs was populated on the first tab hence many multiple items with the same item designation. Very strange issue.
The same project opened from another client had no problem.
The issue was related to windows updates (KB.....) missing on some clients. The working client had a newer build of WIN10 than the others.
I don´t remember the exact KB that was needed and if there is a document describing Windows related prerequisites for Compact Control Builder.