One of the things that makes High Level so awesome is the speed of it's development and growth. Unfortunately, sometimes this means that there are small bugs that cause your user to be logged out.
Also, if there is a problem with a custom script, it can log you out as well. When this happens, you can get a frozen loading screen. It is extremely important to us that this does not occur so if you have that happening, please get in touch with us ASAP so we help troubleshoot it. Most of the time it is a 3rd party script (not ours) or a High Level update that caused the problem.
That being said - here are a couple of ways to get out of the Frozen Loading Screen,
Open in Incognito. The regular browser will clear it's cache in about a day.
Use the QuickEditor Chrome Extension to clear the cache. This is part of a paid membership inside The Marketer's Toolkit.
Clear the Application Cache through the Chrome Inspector.
Close the entire browser and re-open it. You may need to restart your computer.