My first thought would be to run a "dbms check full" in maintenance, if that fails to fix the issue (which it usually does), you should be able to safely do the backup/restore, just default it and restore and don't check "Restore Dimension from backup" (text might be slightly different in your software version).
Beyond that in such a small system I can't image how you wouldn't have enough of any memory allocation in Dimension Selection for any attribute to cause problems.