There's nothing appearing in my extension manager

I think you find the problem!

Unfortunately not.
Your folder-options is set to not show file types.
So the ā€˜extension_manager’ file has no ā€œ.htmlā€ file type showing - but the ā€˜Type’ column to the right shows its type - although you have clipped off the right-hand side, it is still clear…

Try double clicking its icon and report what the web page that opens looks like…

Can it be fix?

Going back several posts you have still not confirmed that you have run a ā€œRepairā€ā€¦
For the avoidance of doubt here’s the full set of instructions to try it…
It should not affect any customization you have already done to SketchUp - like installing Extensions…

  • Log into Windows as your normal user-account - do NOT use a special system administrator account, BUT if your normal user-account has some admin-powers that is OK.

  • Ensure SketchUp is closed.

  • Find your SketchUp installer’s exe file - it’s usually in your Downloads folder.

  • Select the installer’s exe file icon, right-click > context-menu > ā€œRun as administratorā€

  • When prompted choose ā€œRepairā€

  • When it finishes restart SketchUp and see if things have improved…

You should never install any complex app on a PC by double-clicking its installer’s exe file’s icon to ā€œRunā€ it. Even if your normal user-account has some admin powers it is NOT the same thing.
As a result of an improper installation all kinds of unpredictable things can occur, often related to incorrect permission settings, preventing SketchUp [or the user] from saving setting files properly, or reading in files which should be readily accessible.
As I said some days ago, the missing content in SketchUp’s dialog is probably related to it being unable to read its own html file…
Your very recent screenshot shows the content that should appear in the dialog, so the file is OK.

So please ā€œRepairā€ and see if that helps…

yes i did a repair as an administrator and nothing change with this problem, But i don’t have any problem fo doing it again. I’l do it and come back to you.

Unfortunatly it’s still de same

In your screen shot Extension Manager is shown with the Internet Explorer icon. Try installing Chrome and using that. Any change?

Please do the following…
Go to the extension_manager.html file as you did before.
Select its icon, right-click > context-menu > Properties > Security > Edit
Every entry in the list should have at least two of the ā€˜Read’ options ticked.
See my example, attached.
What do yours say ?

In mine i don’t have this ā€œll APPLICATION PACKAGESā€

but i have in each categorie at leste Read and execute and read

My settings might differ because I’m on Win 10 - are you still on Win 7 ?

I’m running out of ideas…
Anyone else like to chip in ?

Seems like it’s getting to the point where an ā€œReinstallā€ might be in order…
Using the exact same steps as in ā€œRun as administratorā€, once again - but this time choose ā€œUninstallā€.
When that completes, immediately repeat the same steps as in ā€œRun as administratorā€, once again - but this time choose ā€œInstallā€ [if offered].
When that completes reopen SketchUp and see if it helps.

Your Plugins folder should be unaffected ?
But if not try reinstalling the Extensions you want/need…

yes i’am on win 7

If i uninstall it, will i lose a licence for a computer?

i did uninstall and reinstall it as administrator and it still de same

do you use explorer or chrome or other? Can that make a difference?

What browser I use is irrelevant.
BUT you might have hit on something…
Newer versions of SketchUp ship with their own ā€˜Chrome’ browser set up.
This should be used for most of of its own dialogs, [using HTMLdialog Ruby rather than the older WebDialog] and this can also be used by Extensions - but many still use the built-in browsers for backwards compatibility…
In earlier versions the browser used by all dialogs was the default system browser - in your case PC = Internet Explorer [Safari = for MACs].
If the Extension Manager is still using the older set up, then it’s using your Internet Explorer settings…
So next question, do you have the most current version of Internet Explorer installed - SketchUp expects v11 - Under Win 10 it’s v11.615? found from ā€˜About Internet Explorer’ - if you have an earlier version, then can you try updating it.
There might be an update option in its ā€˜About…’ dialog, but otherwise look here…
https://www.microsoft.com/en-gb/download/internet-explorer-11-for-windows-7-details.aspx
Remember to use ā€˜Run as administrator’ where appropriate…
You’ll probably need to restart your computer after the update…

I did but with chrome, i can’t download nothing?

You seem to be ā€˜downloading’ OK, but your Extension Manager’s dialog is broken…
That is what we are trying to fix !

Some of this is above my head, but I have 2019 successfully running on a Windows 7 machine. When I installed SU I had Chrome set as my default browser and still is. I have no issue with SU extension manager or 3d Warehouse for that matter.

I just tried Internet Explorer as my default browser and the Extension manager window still opens fine. So things are working alright for me here.