CASSI1710S Error extended-file-status starting single user region, run time lock not acquired

An error occurred whilst starting a single user development region. A run-time lock could not be acquired due to the error extended-file-status. The most likely reason is that the directory in which CICS Option creates the lock file, <project-name>\system, is read-only.
System Action:
The single user region will not initialize successfully.
Resolution:
Ensure that the directory <project-name>\system is not read-only.
Module:
dfheini1
Destination:
Console and standard error