This may occur if the gift being changed have a GL Post Status of Posted. To change the funds on the gift:

Adjust the gift instead of globally changing it

OR

Edit the most recent adjustment instead of globally changing the gift.

OR

If you do not post to The Financial Edge or a General Ledger:
  1. Change the Post Status from Posted to Not Posted.
  2. Complete the global change.
  3. Change the Post Status from Not Posted to Posted.

NOTE if you post to The Financial Edge or a General Ledger: Changing funds in The Raiser's Edge when integrated with The Financial Edge or another General Ledger can cause serious differences in the two systems. Adjusting the gifts and posting the adjustments is the recommend method because that generates the correcting entries for the General Ledger to keep records in both systems in sync.