issues with skyfactory 2.5b

[Shalay]

i tried to log into skyfactory 2.5b today but i got a huge error message about rejected mods but when i tried to log into sf2.5 it worked just fine i was wondering if that is a goof or if 2.5b is supposted to be different than 2.5 i have a screen shot of the error also

 

[FearsomeMango]

I got the same thing after the 12pm server backup. I have not been able to join back since then

 

[KookyKraftMC]

The server updated to 2.5.5.