Compatibility range mismatch
When I tried to run the following PowerShell:
$site = Get-SPSite $spsiteUrl
I got the following error:
There is a compatibility range mismatch between the Web server and database “WSS_Content”, and connections to the data have been blocked to due to this incompatibility. This can happen when a content database has not been upgraded to be within the compatibility range of the Web server, or if the database has been upgraded to a higher level than the web server. The Web server and the database must be upgraded to the same version and build level to return to compatibility range.
Shell admin access
I gave my user account Shell Admin access and then I could access the webs within a site.
All I had to do was give my user account SP_Data_Access permissions on the content database mentioned. I already worried that I hadn’t run an update properly.