Cheats manager AR code adding error

[RevelationOrange]

Every time I try to add a code I've searched for, I get a weird error:

..\..\src\msw\checklst.cpp(263): assert "IsValid(uiIndex)" faile in
wxCheckListBox::IsChecked(): bad wxCheckListBox index
Do you want to stop the program?
You can also choose [Cancel] to supress further warnings.

Yes closes the dolphin emulator, no causes this error to occur every time I try to add a cheat, cancel suppresses the error. "enable cheats" is definitely checked, so I have no idea what's happening.
The code shows up in the AR codes list at the bottom, but isn't saved when I exit dolphin. Checking it and hitting apply has no effect.

[NKF98]

use the latest dev version

[RevelationOrange]

Well, there's no error this time, but it won't even add the cheat to the list, even temporarily

[RevelationOrange]

Ok, so I have definitely been able to do this before, I have no idea what's going on. Strangely, trying to use cheat engine to achieve the same result didn't work.

I'm playing Final Fantasy Crystal Chronicles, and I want to be able to fix the points I have going through each level which determines the artifact set you can choose from. As you may know, each time you go into a level, you either start at 0 and get points each time you do a particular thing, or start at 100 and lose points when you do a thing. This should be a very easy search, but for some reason I can't add the cheat in dolpin (or find the right value in cheat engine).

Any ideas?