So, I decided to visit to the Abyss and wave that Skull of Mondain around, and afterwords tried to get Katrina to join me, and I got the message in the attached screenshot. Any idea what's going on? Why is she saying such glitchy garbage?

i haven't played more than about 3 minutes of U4, but i guess that the game would normally put the name of one of the Virtues where that gibberish is? perhaps there's a bug in determining the number 0-7 of the relevant / requisite Virtue, so it unfortunately tries to read the name from outside of an 8-entry list of names, and gets other unprintable data instead of a valid name / word.

(This is the Sega Master System version. While there are some differences between this and the DOS version, the port is still quite faithful, unlike the NES port which changed a lot.)

Where that chunk of garbage text is, it's clear that the word that's supposed to be there is "humble". Worth noting that the other companions who I checked display the expected message (except that I didn't test Mariah, since my character is a mage and Mariah just says "I cannot join thee." if you ask her to join when you're a mage).

(By the way, the Skull can kill Lord British in the NES version, but not in the SMS version. Apparently, according to one of the Ultima wikis, one of the home computer versions also allows this.)

(Also, I noticed an error in my post ("ways" instead of "wave"), so time to correct that.)

an interesting question is, is the game correctly determining the relevant Virtue and performing the numeric comparison on it, but then screwing up when attempting to print the name of that Virtue, or is the game getting it wrong at an earlier point, performing the check / comparison against a nonexistent / invalid Virtue (ie outside the numeric range 0-7)? if the latter, then the game's not even checking / comparing your actual Humility (in this case) but rather some random piece of irrelevant data.

is it generally possible to recruit that character in that version of the game? if it's checking an incorrect random memory location, then she might seem to accept or reject at random in that version of the game.

It is possible to recruit Katrina in this version, as this version is definitely beatable (I've beaten it, and there's a speedrun on youtube), and as this version, like most, checks to make sure you've recruited everyone by the end of the game, and throws you out of the Abyss if you have not.

I don't remember having any trouble recruiting Katrina in normal gameplay; it's only since I've been proudly waving around the Skull of Mondain that she wouldn't join and I've discovered this bug. I think it's safe to assume that, when I took the screenshot, my virtues were terrible.

Interestingly enough, the NES version has a *different* Shepherd-specific bug. In some cases, the routine to awaken party members when combat ends goes one step too far, and ends up "awakening" the Shepherd's XP, resulting in the clearing of the 512 XP bit. As a result, the Shepherd can't actually go past level 4 unless you manage to avoid the bug somehow. (Fortunately, level 4 is enough to beat the NES version, since it's the level when pirate shops appear, and you don't need to recruit everyone to beat the game.)

Google seems to bring up a post here (could have been mine? I didn't check) with another NES version bug: If you have a full inventory and pick up the Robe, apparently you get garbage text there as well. (I'm not sure if the text terminates or goes on forever. I know the text in the SMS screenshot I posted does terminate, so the bug has no ill effects.)