I had the same issue for a long time. But i fixed it with a work around. I was able to push my branch to origin using github Desktop instead of GitKraken. when i pushed in GitDesktop the Kraken version also updated.
I also had this problem and am just using CLI as a workaround for now. My commit was ~100MB, mostly images.
I have the same error all the time could anyone fix it please?
@wojtekgradzinski this seems to be a problem with GitKraken and their OAUTH system - it would need to be raised with them and get them to fix it since previous posts above say how to get around it, but nothing needed to be done on the Gitlab side, just using other apps or pushing from the console, etc.