To find the RUBY_VERSION, you must open the Ruby Console from within SketchUp - no need to use some confusing text editor extension.
So to open the Console use the built-in menu item Extensions > Developer > Ruby Console.
Type or copy/paste the RUBY_VERSION text and <enter> to get the result...
However, I suspect that step won't get us far... because you seem you have some wrong ideas / confusion about how extensions work ??
For example you list several RBZ files to 'uninstall', which have nothing to do with how any properly installed extensions work... if they are in your Plugins folder you can delete them as they are not 'in use'...
Also how did some of their their names get changed to not include the version suffix ?
An RBZ is simply a type of ZIP file which contains all of the files needed by that extension and and which can be auto-installed using the correct tool.
It might be best also to uninstall any current SketchUcation files in your Plugins folder, before doing a new clean installation.
No need to re-install SketchUp itself...
Do this when SketchUp is not running.
Once any rogue RBZ files are removed, there are only two things to delete from Plugins, a SketchUcation.rb file which SketchUp uses to start the loading of that tool's code, and a subfolder called SketchUcation which contains all of the other code files etc needed by the toolset...
Go to the PluginStore again and download the latest v4.1.3 of the SketchUcation toolset RBZ.
It should arrive with its name and version in the RBZ - e.g. "SketchUcationTools_v4.1.3.rbz"
Save that file into your Downloads folder... Do not rename or open it in any way. An RBZ has no place within your Plugins folder.
If you do not have your browser's download setting configured properly it might do unexpected things with the downloaded RBZ - e.g. it should never try to open in SketchUp [or any other app], it should always download and save into your Downloads folder - and when it does save properly, never rename the RBZ. Fix those browser-settings if necessary...
Assuming we now have the RBZ safely saved into you Downloads folder...
Now open the built-in Extension Manager tool...
Menu item Extensions > Extension Manager
In the dialog that opens there's a button near the bottom 'Install Extension...'
Click that button and find the downloaded RBZ in your Downloads folder - select it + OK.
Accept any warning it gives about trusting the source etc...
SketchUp should now auto-extract its various files and subfolders inside the chosen RBZ and put them into the right places inside your 'hidden' SketchUp Plugins folder... [C:\Users\YOURUSERNAME\AppData\Roaming\SketchUp\SketchUp 2021\SketchUp\Plugins ... edit the user as appropriate] - it should overwrite any preexisting files...
When it's done that, restart SketchUp to ensure everything is synced etc...
Now does the Extensions menu SketchUcation submenu and associated Toolbar exist ?
Hope this helps...
Report back...
