Hello both. Be sure you select Realmud in the T4C client, if you're still not getting in. Have a look at the iplist file. You can right click the T4C desktop icon and click OPEN FILE LOCATION or find it manually at MY COMPUTER > C DRIVE > PROGRAM FILES X86 > T4C REALMUD 1.71 or The 4th Coming (depending what installation you had).
Open the iplist file and be sure Realmud's IP is:
If it is different, then replace the above with whatever is there.
Alternatively you can download the fix here: http://webpatch.net/download/ipfix8-30.exe
Hope it helps.
Also note: It would be better to email these problems to me for a more timely solution.