Be sure to use the e-mail used when you have buy the game...
By example, i have buy diplomacy and entrenchment with a [email protected] but buy sins with [email protected] ...
Need to loggin with first one on Impulse for update dip and ent, need to logout and logging with the second one for update sins...
Your error is similar to the problem that i have know recently after updating the Stardock Impulse client to the Gamestop Impulse client... first pic at https://forums.sinsofasolarempire.com/413445 ...