Issue: Chrome recently was updated from the previous version to 85.0.4183.102. After the update you are no longer able to bring up any Admin Page from AppNav. With Debugger enabled in the browser you can see that it simply spins on search.js.
This worked prior to the update.
All the other browsers work fine.
The issue only exists after upgrading Chrome. This issue has been seen in both Windows and Mac OSX.

Resolution: In one case it was found this issue was due to corruption in the 'Local State' file which resides in the 'C:\Users\<username>\AppData\Local\Google\Chrome\User Data\' directory
On Mac OSX the file resides in the /Users/<username>/Library/Application Support/Google/Chrome/Default/ directory.

Workaround #1:
Save off your Profile, eg - make a copy of this directory to another location outside of User Data
Windows:
C:\Users\<username>\AppData\Local\Google\Chrome\User Data\<YourProfile>\
Mac OSX:
/Users/<username>/Library/Application Support/Google/Chrome/Default/

Next with the Chrome application closed, delete the 'User Data' folder in here
C:\Users\<username>\AppData\Local\Google\Chrome\

Open Chrome back up.
It recreates the User Data folder.

Now you can test Admin Pages at this point to verify if it works.
Once you have verified it's working you can then copy your profile back into Chrome 'User Data' folder to recreate the profile.

Workaround #2
If removing the User Data and recreating the profile does not work:
Uninstall Google Chrome.
Reinstall Chrome and make sure it's upgraded to the latest version.
Then place your backed up profile in the directory again.

Admin Pages should work now.

Related Information: CR-000175553 - BannerAdmin spins and hangs in Chrome browser and displays Javascript error Uncaught RangeError Maximum call stack size exceeded
Article 000039688 - BannerAdmin spins and hangs in Chrome browser and displays Javascript error Uncaught RangeError Maximum call stack size exceeded