I had the same problem with 4.26 install and this did the trick. Thanks.
*> Hey zebracan,
There will be hotfix soon that should
fix this issue but in the meantime
give this a try:Login to the Launcher
Login to unrealengine.com
Signout of the Launcher
Click the “Don’t have an account?”
link on the login windowAccept the EULA that pops up in the
browserLet us know how it goes.
Cheers,
TJ*