This has been reported a few times and from what I've seen, a solid consistent fix is not available. You might try going to DCC port options:
ALT+O > Connect > Options > [Advanced...]And check
"Bind sockets to IP address" and then put in your LAN IP.
It might be an FServe script error as I manage to resume perfectly well on 6.14 and have never experienced this error. You can get "invalid parameters" when the DCC exploit is attempted to be used against you, however, that shouldn't happen in a Resume situation.
This thread might interest you.
You could also do a Forum
Search for something like "invalid parameters" and see what other threads you can find, and see if their solutions may help you. Expand to 'All Forums' and 'All Posts' to benefit the maximum number of results.
Hope it gets sorted
Regards,