TITAN will have this error messages in the event of one of these instances. If the disk is really full or if it has reached the Disk Free (%) or if the table size for the database is too small.
To change the Disk Free (%) in TITAN, go to File > User Preferences > Miscellaneous tab
In PCs this day and age, with Hard Disk space being an abundance, it is OK to have it to as low as 2%.
To change the table size of the database, close TITAN then go to:-
Start > Programs > TITAN Security System > Database Administrator
In Database Administrator, go to:-
Configuration > Drivers > Native > PARADOX > Change BLOCK SIZE to 32768
Go to Object > Apply to save changes. Restart TITAN.