Finder Won't Open Files in Monterey 12.6.4

Thank's for your help. The symptoms seem the same but apparently the causes are different.

Something I don't like is that without doing anything special, the problem goes away. This is what happened after rebooting!

Now it works just like before: whether I use Preview or skim, my pdf files open when I click on them, same for Word or Excel files which didn't open when I clicked on them! How long will this continue to work? I cross my fingers.

It is strange that Apple's engineers don't show more reactivity to what seems to be a bug in Finder with multiple causes...

Some precisions. It seems that my problem has 2 origins:

1) the use of SKIM whose latest version seems to be buggy on Monterey at least. Now I open all pdf files with Preview and itt works...

2) the file name must not contain any special characters like @, otherwise the file will not open when clicked... I read somewhere that even blank characters in the name cause problems.

Hi riccifromsunnyvale, It has nothing to see with what you say.

I have a short pdf file, no special characters in the title and it dosen't open.

I restarted in safe mode, it solved the issue for a few days, now, it's back again.

As safe mode cleans caches, this is where I should look at, I think...