This one is very easy to duplicate.

Add the variable #+STARTUP: indent to the top of the org buffer. Hit C-c C-c with point on the startup variables to refresh the setup.

Create a todo item. Assign it priority A via C-c , A. Then reassign it priority B via C-c , B.

When indent mode is enabled, you will get an error stating "args out of range -1, -1"

When indent mode is not enabled, reassigning priorities works.

I suspect it can't find where to replace the priority because of something in the star hiding mechanism of indent mode.

Thanks,
JB

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