Symptoms: When attempting to open one or more databases in JOB Plus or JOB Cal, you receive an error message, Error 3051,  stating that the Microsoft Jet database engine could not open the database file due to a permissions issue or the file is opened exclusively by another user. The program exits promptly after you confirm the error message.

Possible Cause #1: The JOB application exited unexpectedly and left a lock on the database file (.mdb).

Solution to Cause #1:  The easiest solution to this problem is to delete the lock on the database.  The lock file is a file of the same name; however, it has an LDB (.ldb) extension instead of an MDB extension.  FIRST, with JOB, ensure that no users are logged into the system and then delete the .ldb file.  (i.e., if your facility's database is call RockyCreek.mdb, manually delete the RockyCreek.ldb file)

Possibly Cause #2:  The Microsoft File system has, for various reasons, created an NTFS file lock on the facility's main database file (.mdb). 

Solution to Cause #2 FIRST, ensure that no users are logged into the JOB database that you are attempting to fix.  Then, create a copy of the facility's database file (.mdb) either in the same directory or in another directory/drive.  Then, rename the original facility database file: i.e., rename RockyCreek.mdb to RockyCreek_BAD.mdb.   Next, rename the copied file (Copy of RockyCreek.mdb) to the original file's name (RockyCreek.mdb).  Now, try accessing the facility using the computer that received the 3051 error.  If the problem is corrected, you may delete the bad file (RockyCreek_BAD.mdb).