Can you both please try the text in the Ruby Console I prepared earlier...
You are using different operating systems...
But one thing you both have in common is your user-name is in capitals and starts with a U.
I'm assuming you haven't edited the text you posted...
There were reports some time ago about this kind of issue.
SketchUp's Ruby can see the /U in a string as a Unicode escape character - and this breaks the UTF-8 text format it's hoping to be using... Not sure if lowercase /u has the same issues ? Hence the encoding error message at the start...

Can you try a change in your user-name to use all lowercase characters, or NO U after a / at all, restart your computer and try again ?
I'll look at ways of trapping this error, if it's possible...

@gullfo

This is a previously unknown, and so far inexplicable, error.

How many Plugins folders do you have set up ?
Do they all have .RB files in them ?

To find a list can you please do this:

Open SketchUp

Open Extensions > Developer > Ruby Console

Copy/paste this as one line:
puts "\nDefault:\n#{Sketchup.read_default("SCF", "DefaultPlugins", "???")}";lp=SCF_Dialog.getMyPluginsFolders();puts"\nAll:\n#{lp}\n\nContents:\n";lp.each{|p|puts Dir.entries(p).size-2 };puts"\nRBs:\n";lp.each{|p|rbs=[];Dir.entries(p).each{|f| rbs<<f if f=~/rb$/};p rbs.length};puts;

Press enter

Copy all of the returned lines and paste them into a reply.

@Jspro

You are NOT getting the properties of your *Plugins folder - that's the SketchUcation.RBZ !

In any case your user account was not highlighted in the dialogs that you snapped.

If that* was and has checked 'Full' [first item], even if it's 'greyed' it should be OK.

Can you please learn how to make PC based snapshots of your screen or dialogs without resorting to actual photographs - it makes reading this very awkward...

Late on in 2017 they changed the menus etc.
Preferences no longer linked you to Extensions.
The equivalent Extensions Manager then appeared under the Windows menu,
later on this migrated again - this time into the Extensions menu.
The Extension Manager has its own dedicated dialog,
with an Install Extension... button to do exactly what the earlier way did.

@Jspro
All or the files and subfolders in your plugins folder [path in the error messages] should have appropriate FULL permissions.
Try the following:
Select the 'plugins' folder's icon, right-click > 'properties', then 'security' tab, your user-name should be listed, choose the 'edit' button and ensure that you have 'full control' set up. Choose 'apply', then OK.

Our v5.0.1 is now published in the ExtensionStore.
This traps for sloppy extension creation without a version being set.
After you install that you can restart SketchUp, and then restart using InstantArchitecture without any clashes...

I'll defer to Gábor... but it looks like you are trying to login to the SketchUp/Trimble Extension Warehouse, which isn't supported in v2017 ?
What did you click on immediately before the error dialog ?
Are you actually logged into SketchUp [using the connected email address] ?
If you want to open the SketchUcation ExtensionStore to download extensions, you do that either through the red-toolbar button or Extensions > SketchUcation submenu item, logging in using yur SCF member-name and password.
If you don't have that SketchUcation Toolset installed for that user-account [it's not clear from your picture] download its RBZ [at the moment that's version 5.0.1] from the SketchUcation PluginStore web page and install that using the Extension Manager dialog red-button [shown in your picture]; restart SketchUp and the SketchUcation ExtensionStore should be available to you thereafter...

v5.0.1 is now available in our ExtensionStore.
It traps for the earlier error, which resulted from your loading-extension not having a valid version set up.
https://sketchucation.com/pluginstore?pln=SketchUcationTools

Probably OK - try it...

The culprit is "InstantArchitecture = " which does not have a version set up properly!
Our code assumes some version for every extension, even if it's blank "" - but yours is 'nil'.
We can add code to trap for this rare anomaly.
After exhaustive pre-release testing this is the first report like this.
This update might not be published for a while, so in the meanwhile try these fixes.
Disable 'InstantArchitecture' in the Extension Manager [or our Plugins Manager] and restart SketchUp -
our ExtensionStore should then work OK.
Alternatively, get an update from the author which has a proper version set and install that and restart SketchUp.
Or edit its register file in the Plugins folder [InstantArchitecture.rb] with Notepad++ or another plain-text editor - add a line saying VERSION = '0'
Save and restart SketchUp, as it's version is now set to '0' the ExtensionStore error will stop.
Where did you get this extension from ? It's not listed in our PluginStore. In the Extension Warehouse 'Instant Architecture' by Chuck Vali has no version listed so I guess that's the one... As its subscription only from his site I don't know the exact code structure, the VERSION = '0' fix won't break anything in the code provided that you have your Extension Manager's Loading Policy set to Unrestricted [if it's signed] - after checking it that extension is ignored anyway as it's not in our Store so is not checked for an update, which is impossible with the versioning it has anyway...

@daydreamdesign

Sorry, but that is not the message ! Or if it is it's not the whole thing.

Please follow the instructions again and post the resultant output.

This should consist of:

1. a number of possible Plugins folders paths/names, inside []
2. the default Plugins folder path/name
3. a list of several lines - 'extension_name = version'

@daydreamdesign

Something is going adrift with the code being able to get an extension's versions.
This then causes the error.
Can you do the following and copy/paste the results in a reply.
Open the Ruby Console [Extensions > Developer submenu item].
Copy paste this code and press enter...

puts SCF_Dialog.getMyPluginsFolders;
puts "\n___\n\n#{Sketchup.read_default("SCF", "DefaultPlugins", "?")}\n\n";
Sketchup.extensions.each{|ex| puts "#{ex.name} = #{ex.version}\n" };
puts "\n___\n";

It might show up some unexpected errors...

And if you erase that file you will need to re-validate the licenses...

His tools are no longer supported.
Sadly he died some time ago...

@fredo6 might be able to comment more helpfully on that error code, but one thing springs to mind - to communicate with SketchUcation.com your firewall settings should 'whitelist' the site - otherwise the licensing falls at the first hurdle...

Make post here with the relevant details and screenshot etc.
@Fredo6 will see it.

Can you provide screenshots of where it 'sticks'.
Are your username and password both exactly as set up for the main web site ?

Please note that Fredo's 'RoundCorner' is a different extension to 'FredoCorner'.
They have their own licenses.
You cannot license one of them with a license file that is for the other one...

@JKDEKO
If you are using Fredo's extensions you also need to install the SketchUcation Toolset which manages the licensing, and LibFredo.
If you have the Toolset install you can browse and auto-install these extension/lib files without having to get an RBZ file etc.
To install the Toolset download its RBZ from this link...
https://sketchucation.com/pluginstore?pln=SketchUcationTools
The use the Extensions > Extension Manager dialog to install it for you. Restart SketchUp to sync everything...

Si vous utilisez les extensions Fredo, vous devez également installer SketchUp Toolset, qui gère les licences, ainsi que LibFredo.
Si vous avez installé SketchUp Toolset, vous pouvez parcourir et installer automatiquement ces fichiers d'extension/librairie sans avoir à télécharger de fichier RBZ, etc.
Pour installer SketchUp Toolset, téléchargez son RBZ depuis ce lien :
https://sketchucation.com/pluginstore?pln=SketchUcationTools
Utilisez la Toolset de dialogue Extensions > Extension Manager [Gestionnaire d'extensions?] pour l'installer. Redémarrez SketchUp pour synchroniser le tout...

The earlier posts in this thread explain how to make a temporary fix by editing the RB file.
В предыдущих сообщениях в этой теме объясняется, как сделать временное исправление путем редактирования файла RB.