So I can't figure out how to scribe spells. I have given the scrolls to suitable characters (red MU scrolls to red mage, and white MU scrolls to white mage). I encamp, go to magic, scribe, but then the game says "no copyable spells". In items menu when trying to ready the scrolls (even with Read Magic on) the game says wrong magical order. When trying to ID the scrolls in a store, they say that they can't tell anything new about them.

Am I doing something wrong here?

Maybe the character's INT is too low?
You need 18 INT to cast lvl 9 spells, for example.

You can view the scrolls and see which spells they contain, right?
If you can they are scribeable.

Also, I seem to remember there being a bug with the colours for some scrolls. So try scribing scrolls of opposite colour of the mage and see if that works.

Both my mages have int of 18, so that doesn't seem to be the issue.

The scrolls are just named "Red MU Scroll 3 Spell" or "White MU Scroll 3 Spell". I tried to switch them around but no change.

I'm playing Champions, if that matters.

What happens if you try to Use the scrolls? Can you cast the spells in them?

I can't use them, because they need to be readied, which I cannot do because the scrolls are of "wrong magical order".

Clerics don't seem to have this problem. They can use their scrolls just fine.

IIRC, you have to be a high enough level to cast a spell before you can scribe it. That may be the problem.

I don't remember running into this issue when I played through the game last time, but it sounds like it could be a bug of some sort.

What alignment are the Magic-User chars?

My MU characters are:
True Neutral Qualinesti Elf, Sirrion Cleric / Fighter / Red Mage, levels 5/6/5
and
Neutral Good Human, White Mage, level 7

I've been using Gold Box Companion, so there is a chance that something has glitched out.

As I mentioned in my last post, I think Gold Box Companion is the source why the scrolls won't work as intended. I downloaded and installed the newest version, and in the changelog it says, that problem with auto-identification and scrolls has been fixed. So I acquired some new scrolls and they work just fine! I guess I could make the scrolls work by tweaking with GBC, but I don't know how.

Thanks for your insights anyway.