Thread:Project:Support desk/Post 1.19 - 1.21 upgrade: Nested table formatting fail

Hello, I just executed the upgrade from 1.19 to 1.21 (on windows) at a customer site. The process was flawless, however the one casualty of the process seems to be that the wikitable styling does not get applied to nested tables.

The following code sample rendered nicely before the upgrade:

Is it possible that I missed updating an extension or something? It does not appear that the base installation was modified to include any custom, or updated extensions prior to performing the upgrade.

Any assistance is appreciated. Thanks !