Subtype code and descriptions not saving

[JayHodny]

Using the Create/Manage subtypes tool in Pro 2.6.x and 2.7, I can add codes and descriptions on an integer field, press OK, the the changes appear in the subtype table.  When I click on Save in the main ribbon, I am greeted with this error.  What am I doing wrong? Thanks.

[JayHodny · Accepted solution]

I believe I have figured out what was wrong.  The FGDB I was using was at version 9.x.  Once I upgraded the FGDB to 10, I was able to save the subtype codes and descriptions in the Create/Manage tool.