Attempting to OPEN a device that is already in use by another process.
Attempting to OPEN a channel that is already OPENed.
Attempting input or output on a channel that is not OPEN.
Attempting to UNLOCK a file that has not been LOCKed or which has been OPENed with an ISZ= option.
Attempting to ADDR a program that is already ADDRed.
Attempting to CLOSE a channel that is not OPEN. PRO/5 issues the error only if the ERR= option is present.
Attempting to LOCK a file that was OPENed by a different user.
Attempting to LOCK a file that was already LOCKed by the same user.
Attempting to ERASE a file you do not own.
Printer lockfile in a directory without r/w permissions.
Attempting to bind a data channel to a data-aware grid using Grid SENDMSG() Function 80 and specifying a channel that is not open.