RAT won't make your clients freeze, as it simply cannot do that. It is just a telnet connection to the server, of which there can be dozens if not hundreds. It is more than likely a mod causing issues.
If you think it is a mod that is required by RAT, you'll need to speak with those mod authors, I can't do anything about those. However, hundreds of people run RAT without this issue, so odds are, its not RAT/the mods RAT requires.
The only thing I can offer at this point is, I'd remove all mods (delete them) and copy them back in, and speak with the mod authors.
If you think it is a mod that is required by RAT, you'll need to speak with those mod authors, I can't do anything about those. However, hundreds of people run RAT without this issue, so odds are, its not RAT/the mods RAT requires.
The only thing I can offer at this point is, I'd remove all mods (delete them) and copy them back in, and speak with the mod authors.
