It could be because of a client/mod u are using.. Are u using a mod that has armorhud etc? If so.. It has something to do with that. Try a normal version then try the mod version u are using. If the normal version works then it has something to do with the mod version.
Shouldn't be an issue if you can connect to other servers can i know which cracked launcher you are using? may be an issue with that specific launcher, try using another one?
Uhmm, this issue happen to me in kohi and other servers before when I was using 5zig.. Strange how this happened to me. But I tried a different version and it worked and I could play. So I thought if Terry did the same, maybe it could help and she/he could be able to play.