isCOBOL IDE or Eclipse error "Workspace in use or cannot be created, choose a different one"

Whenever the Eclipse (or isCOBOL IDE) opens a workspace, it attempts to lock a specific portion of the .lock file in the workspace .metadata folder. If the file .metadata/.lock does not exist, then Eclipse creates and attempts to lock a portion of the file. If the lock attempt fails, then Eclipse reports an error message:

Workspace in use or cannot be created, choose a different one

This usually means that there is another Eclipse or isIDE.exe process running and using this workspace.

So if you see this message it is a good idea to check your taskbar, task manager or process list and switch to or kill the Eclipse or isIDE.exe process that is holding the workspace lock.

If you have verified that there is no other Eclipse or isIDE.exe process running and yet still see the error message, it may be due to a permissions problem or an operating system lock release problem (e.g. on Windows) and the sure-fire remedy is to simply delete the .lock file and restart Eclipse.