Common error codes:
1 - Unable to open database
2 - Database corrupted
3 - License checksum failure
4 - License limit exceeded
5 - License limit exceeded
6 - Product not licensed
7 - Unknown license failure
8 - License DB too large
9 - Heap error
10 - Cannot contact License manager
11 - Message send failure
12 - Message receive failure
13 - Returned checksum failure
14 - Integrity check failure
15 - License limit exceeded - no overdraft
16 - License limit exceeded
17 - License limit exceeded
98 - User tampering with license system
100 - User tampering with license system