Moved to Composr project; I'm assuming you didn't mean to put this in compo.sr because you're not an admin of the Composr site. :P

True. Sorry. And THANK YOU!

Try upgrading to 10.0.50, clear all caches and cookies, and let me know if that works. 10.0.50 reverts some things from 10.0.49.

I'm re-classifying this as a minor bug. It's not major because it doesn't break the entire site.

Also note v10 is now in long-term maintenance status, and thus is not receiving funding anymore for non-critical bug fixes. So if you still have an issue after upgrading to 10.0.50, I cannot help unless you hire me to look into the issue.

Thanks, @Patrick for all your help.

I did all what you mentioned. Upgrade to 10.0.50. Cleared all caches and cookies in Chrome and Firefox.
It seems that admin login loop somehow works fine, But another problem raised:

I can enter the text for Adding News, also a picture is now possibl to add and it shows properly. But the two buttons below are not working: Preview and Add news.
This is my main feature - adding some news daily. I tried before with work around- to add a code manually under Source, and upload each picture manually.
Now to upload a picture works fine, but Add news is not working.

All your efforts are very apreciated. I will wait, I am not a programmer, so I am fully depended on you guys! Thank you.

(Click to enlarge)

IT WORKS; IT WORKS!!!!

@patrick, ALL works fine now! So sorry to interrupt. I did several checks, and now a new feature is up. Besides time I need to enter AM or PM.
So, I did not receive any error message, only Add news were not working.

But WORKS FINE NOW!!!! Thank you!

Good to hear. I will close this issue in that case.