@tig said:

I assume you have the latest TT_Lib installed - needed to support all of thomthom's extensions...

Next - the error message you are seeing is because SketchUp is failing to load the html code used to make the CleanUp dialog.
This suggests that either SketchUp is not initially intstalled properly, or the extensions are not being read-in properly.

When you reinstalled SketchUp did you do it as follows ?
This covers a new and a repaired installation on Windows...

Log in to Windows as your normal user-account - NOT any special 'admin' account, but if your normal user has admin powers then that is OK.

Ensure SketchUp and Layout are closed.

Find the SketchUp installer's exe file - usually in your Downloads folder.

Select that exe file's icon, right-click > context-menu > "Run as administrator"

When prompted... for a new installation choose "Install", for an existing installation choose "Repair".

SketchUp should now be set up with the correct permissions.
Any existing customization - like Plugins - should be left unchanged, and when SketchUp is launched the settings should now be resolved properly...

Try it and report back...

Try reinstalling any flaky extensions...
A few are known to have their preference-files screwed by earlier wrong permissions - if you get those please report details and we can try alternative fixes for these - usually deleting badly formed files...

Hi. Thank you for answering back.

I'm using SketchUp's official installer, latest version from April, from their website,

Installing [a few days ago] and repairing today as admin still did not work.

After I formatted the computer the other day, I deleted the files under Users/Roaming/SKP2020 [and other versions].

I notice that even after I installed 2020, I'm seeing folders named 2016,17,18 and 19 under the Users/Roaming folders. IDK if this is normal.

Basically, I wiped everything, even ran CCleaner.

Any other advice?