Text: "The procedure entry point hb_ot_layout_table_get_script_tags could not be located in the dynamic link library C:\Program Files\Firefox Nightly\xul.dll."

And when I click "OK" button, the next error is: "Couldn't load XPCOM".

Was this fixed by the next update, or was the updater also unable to run? You might need to manually run the latest Firefox Nightly installer. It should detect the presence of your data and do an in-place update (refreshing the program files).

https://www.mozilla.org/firefox/all/desktop-nightly/

After the release of a newer version, I manually downloaded the installer and reinstalled the browser. Now everything works. On the previous version, this operation did not help.

!!! But I want to draw the developers' attention to this. There is no mechanism for reporting an error in the situation that I had. And it's a shame that there is no built-in mechanism for fixing such a launch problem !!!

If you want to be a tester of these Nightly development channel builds that gets checkins and updates twice a day then you may be interested in the daily threads in https://forums.mozillazine.org/viewforum.php?f=23

The Nightly channel builds are a work in progress, especially when a new version number starts on the channel.

An error message about XPCOM missing usually happens because of a failed Firefox update that left you with a mixture of old and updated files in the Firefox program folder. This can happen due to security software keeping a handle of some of the files in the Firefox program folder preventing Firefox from replacing all the files. You need to do a clean reinstall and remove the Firefox program folder to ensure that all files are replaced an you may have to disable security software temporarily in case the problem persists before reinstall.