I use right mouse button to jump and have it set that way in settings. But every time I launch Blood, right mouse button is walk forward. If you check Blood.cfg it is configured properly. I'm guessing DOSBOX is doing something?

All the other bindings seem to behave. It is only right mouse button that is a problem.

Check your blood.cfg file if you want richt-click set to jump, you probably want it set to something like this:

MouseButton2 = "Jump"
MouseButtonClicked2 = "Jump"

The game isn't installed to a protected folder, is it, resulting in the config file not actually being saved?

I have:
MouseButton2 = "Jump"
MouseButtonClicked2 = ""
which doesn't work. So I updated to
MouseButton2 = "Jump"
MouseButtonClicked2 = "Jump"
Which didn't work either. I thought you had it, as Blood is a protected folder (though opening Blood.cfg still showed my settings). But I did make it a non-protected folder. I also turned off cloud syncing. But neither helped.

If I use Launch Settings and choose Save and Start Blood (or whatever that last option is) it works. But if I use Launch One Unit Whole Blood, the stupid right mouse button remains 'walk forward'. Now, to be clear, if I exit that and use Launch Settings again, the mouse shows to be configured properly. I am NOT having to reset it every time. it's more like One Unit is just not following Blood.CFG or something. And the other two mouse buttons (left=Fire, middle=Alt Fire) work correctly. It is only the right mouse button that is making me cry.

Is it possibly something in DOSBOX?

It's possible. And it might be that you have some additional software/drivers for your mouse that DOSBox is misinterpreting, but unless your right-click is mapped to your move forward key up-arrow or "w" in a wasd type setting, I doubt that is the issue.

Do you have any MouseButton mappings that are set to walk forward anywhere? Perhaps even in an additional CFG file? If blood.exe sees additional CFG files it will ask which one you want to use when the game launches.

I don't. But reading your message proimpted me to do something I'd coonsidered previously. I launched settings and saved the file as Settings.CFG. Then when I clicked Launch Blood, it asked me which to use. I chose my Settings.CFG and that seemed to work. I'll play with it a bit more before marking this as solved.

I hope I don't have to specify which CFG file to use each time I launch. But if I do, that's less frustrating than what had been happening.

IIRC, if it only sees one CFG file, it will just go with that, so you could try moving the old blood.cfg file out and just leave the Settings.CFG

I renamed BLOOD.CFG to BLOODCFG.TXT and when I launched, the game still wants me to specify between BLOOG.CFG or Settings.CFG. I'm guessing that there's a hidden BLOOD.CFG the game is looking at. That could explain why the BLOOD CFG file I was looking at was fine, but the game saw something else.

Also, it lists the two files as:
a: BLOOD.CFG (DEFAULT)
b: Settings.CFG

Is there a simple way to make Settings.CFG the default?

I don't think there is. I checked the help for the Command-line Options and there isn't a -cfg switch

Solved it!

There is a SECOND BLOOD.CFG file stored in the 'cloud_saves' folder. So for me it is located as C:\GOG Games\Blood\cloud_saves. That one still had the mouse button set to Walk Forward. Editing that CFG fixed the problem.

When you launch settings, it updates the BLOOD.CFG stored in C:\GOG Games\Blood\ But when you launch the game, it loads the CFG saved in C:\GOG Games\Blood\cloud_saves.

Looks like I can't tag my own post as a solution (why not?), so if anyone wants to quote this message I'll mark it as the solution.