After you add new client regions, collectors will not reload.
If the newly added client regions (manually or through csv import) have networks that overlap, the collectors will error out during reload.
Delete the client regions that have the overlapping networks and reload the collectors. After they are up and running, you can re-enter the client regions that were deleted previously. This time, edit the definitions to make sure that networks do not overlap. There is a mysql query that can be run on the master console to identify overlapping networks saving a lot of troubleshooting time. This query is long and should be broken up into two sections and copied and pasted over to the command prompt. SELECT cli_id, inactive, HEX(start_address ^ end_address) FROM `clients` where (start_address ^ end_address) not in (0, 0x01, 0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff, 0x1ff, 0x3ff, 0x7ff, 0xfff, 0x1fff, 0x3fff, 0x7fff, 0xffff, 0x1ffff, 0x3ffff, 0x7ffff, 0xfffff, 0x1fffff, 0x3fffff, 0x7fffff, 0xffffff, 0x1ffffff, 0x3ffffff, 0x7ffffff, 0xfffffff, 0x1fffffff, 0x3fffffff, 0x7fffffff, 0xffffffff); The above query will give you a list of client regions with overlapping networks. Run this again after resolving the problem to make sure that the issue has been resolved. You should get an empty set result with no warnings.