hero not upgradable or able to use in team

[darwin9000]

Hello everyone! Im struggling with a hero of mine being unable to upgrade rank, attribute and abilities. Upon leveling him up i get the message 'lost connection to honorbound servers', when i log back in the upgrades are reversed! 

I also cant swap him into my squad! the heros name is 'Rimeholm Cabalist' mythic from an event awhile back.

Any help would be appreciated