That message tells you that the Cache-A's internal database of all catalogs has become corrupted (basically a mySQL error). This usually can be easily repaired by ProMax support or by anyone logging in through Cache-A's maintenance login. The process is not difficult but any errors could cause bigger problems.
I recommend that you contact ProMax support to get this fixed, but if that doesn't work for you and you are comfortable using a command line, please send me an email directly and I'll provide the commands.
30201 Rainbow Hill Rd.
Evergreen, CO 80439