I set the fill limit to 1 million, but when I tried filling in the area with air, it gave me the error that the area exceeded the limit of 32768 blocks. Then when I actually split it up into little slices and set the fillUpdates to false, there was still lava flowing when I tried making the perimeter.

Should be fixed in v1.2.1

Hmm, where u running any other mods?

I was, and when I tried again they both worked, but there is a new weird bug in that it wouldn't show the number of blocks that had been removed or selected for removing, it only shows the limit.

What are the other mods u r running? Also could u provide a log of the game where this bug occurs

that time I was running no other mods