Mass Blocks placed prior to 1.190 are broken
Artificial Mass Blocks on ships placed before update 1.190 no longer function. They show 0kg, while new ones placed after show 50000kg. Grinding/hacking and re-welding does not fix it either.
ALSO: New mass blocks are unaffected by old gravity generators. Replacing all old gravity generators and all mass blocks is required to continue using gravity drives.
This seems to affect all blueprints contain mass blocks.
Attached is a new world created after 1.190 with a ship that contains a mass block from an old blueprint that is broken, and a new mass block that is functioning.