New Known Issue that I am reporting:
What I did:
Ran auto-update through Softaculous.
Agreed to allow a backup copy to be made and hit "Submit" and let the window run to 100%.
Next Screen directed me to the actual update page, so I clicked the URL
I clicked Accept for the update and let it run
At end of update I clicked URL to enter ACP
In ACP I saw Red Banner telling me to delete Install Folder
Went into File Manager to forum folder and deleted Install Folder
Went back to ACP and refreshed, and noticed red banner was gone
Went to Board Settings and clicked "No" radio button for Disable board
Clicked "Submit" at the bottom of the page
Opened another tab and entered URL for Forums
What I witnessed:
Forums were accessible, however the default style was not working
What I expected:
I expected the css style to work and the forums to be presented correctly
How I fixed it:
I went into ACP
I tabbed to Customize and was unable to access any of our styles
I then tested to make sure ProSilver style still worked, which it did, which told me something was wrong with our styles
I went back into the File Manager
I navigated to Styles and noticed that only ProSilver was in the style folder
From a backup I took, I made a compressed .zip of all the styles we use
I uploaded it to the styles folder
I decompressed the .zip file into the Styles folder and confirmed they were there
I went back to the ACP and refreshed the tab
I then went to Customise and saw our styles were there
I went back to Board Settings, and re-enabled our default style at the bottom and clicked "Submit".
I went back to the tab I opened for the forums that showed the ProSilver and refreshed it to find that our default theme was again working.
Hopefully this helps someone ☺