Right before playing an online game with friends, I thought it would be better to change my download region from Dallas to Houston in the Steam Settings, since I live in Houston.
Steam immediately asks for a restart, and then nothing I could think of would allow me to login again. I would simply get a “Could not connect” error. Offline mode was not even an option.
If you happen to have done this; deleting the file C:\Program Files (x86)\Steam\ClientRegistry.blob fixed it for me. It will download some Steam updates, then prompt you for your password again. But it will let you login again also.
Hopefully that might help someone out there.
