Old app not running like before

I have this 2,10 MB old app (from 2008) that used to work fine on my desktop PC. Yesterday I tried to run it, it was launched but its main interface didn't show up like before, though its icon appeared in the system tray. I have the same app installed on my laptop PC and it runs normally, as you can see in this screenshot:

I guess this has to do with the two different Windows 10 versions I have running on these PCs.

BTW, today I installed the newest Windows 10 update, which changed its version to 21H2. Yesterday it had the previous version. That app issue is still here.

I tried to run it using Compatibility Mode TNA.

Ideas? TIA.

PS.: if someone wants the app for testing, I can share it, it's freeware. It's standalone, no need to install.

Windows 10 Pro 21H2 19044.1348

dalchina said:

Please post a link, or if small, an attached zip file..

I zipped it, 2,8 MB in size. May I attach it here?

dalchina said:

There's a size limit- don't know how big offhand- try it..

It's bigger than the limit. But there you are:

ClubeOnLine.7z - Google Drive

dalchina said:

Appears to run ok..

What's your Windows 10 version? Or are you with 11 already?

dalchina said:

Please see my specs...

Sorry, I forgot about the specs there!