Thanks this issue has been fixed for the next version. The channel central dialog was processing the limit value as a number (which seemed reasonable) and was performing sanity checking on it to make sure a user entered a valid value/range. However, it should not have been doing this as the client has no idea what the server considers a valid value/range in this case. The next version of mIRC will treat the limit value as plain text and will show exactly what the server has provided.
The issue with the server, where an integer overflow is caused by the invalid value/range you sent, will need to be resolved on the server side.
