Correction: just RoE.

Then it's even more of a disaster. I didn't buy it, I just looked at the screenshots. They ruined the idea, and now fans will trust such "remasters" even less.

Today, Heroes and the HD mod need to be installed in a folder to which you have full access.
Such a folder is NOT: System drive\Program Files (x86)\...
Installing it outside of Program Files doesn't always solve the problem either, if your Windows account has some additional restrictions. Plus, an antivirus program can interfere with the HD mod.

I've already figured this out empirically. It seems that all problems are solved by checking the box "Run this program as an administrator" in the "Compatibility" tab for each executable for all users; with updates, this specifically applies to HD_Launcher.exe and _HD3_Data\HD3_Update.exe.
Besides, there is always the possibility to download and install the update manually. Thank you for the comment.

If you do it the way you suggest, first checking for updates and then launching the game, it will increase the game's startup time.

I understand. I won't argue.

Actually, it's enabled by default. It seems that in this case, the HD mod again has a problem with accessing its files.
But if anything, this can be enabled/disabled in the game: system options -> show object messages.

Yes, I already found it in the game. I might have even unchecked it myself and not noticed - I got lost in the abundance of features.

set the value to 1 - the CPU load decreases.
If, at the same time, mouse lag appears (it will if you have a mouse with a high polling rate, some kind of gaming mouse) or other lag, then set the value to 2
if the lag is still present, then return to 0.

And here, can you elaborate? Reducing the polling rate of input/output devices? What exactly does this parameter change with different arguments? I happen to have a gaming mouse with a 1ms polling rate, and the cursor sometimes "sticks" in the game. At the same time, the CPU cores are not loaded to 100%. I'll try it, thanks.

I'm still going through the new campaign on the impossible difficulty level :cool:, remembering how to play and looking at new features. I've already answered many of my questions in the process of playing. Documentation would, of course, speed up the learning of all the new features, but I completely understand you in terms of time and fully agree with the "as is" policy. I just wanted to describe my impressions on a large scale and provide feedback. I am personally very touched by your work, thank you very much again. I think this is generally important for the developer, and that's why I "got lucky" with a response.
If it becomes relevant and necessary later, when I master everything, I can try to participate in writing the documentation. Slowly. For free.