Alright, thanks for the data...
I believe that the 2.5.1.12 version is (strangely) working because of a bug that was fixed in 2.5.2.1. That bug allows an illegal filter position in the centering override field to just default to the first filter in the list (in your case it is LUM). This issues was fixed in 2.5.2 and properly disallows illegal filters and shows "None" instead. Centering fails when SGPro tries to switch to the "None" filter. To fix this, I think all you need to do is go to the plate solve tab and explicitly set your centering filter to LUM (using 2.5.2.1 of course). I have added some code to make this issue a bit more clear when it happens.