You have the option of delete one or many fixings as a "bulk" update. This enables you to choose Undo of several deals at one time.
Front Office > Modify
Instructions how to Undo interest fixings in Modify View
Step 1: Access the Modify view found in Front Office
Step 2: Search your deal or deals that you want to Undo interest fixing using the Selections.

Step 3: Check- mark the specific transactions of which you want to Undo the interest fixing
Step 4: Click on the three dots "..." -> and click "Undo Interest fixing"

This will delete the interest fixing and reset the "Fixing Status" of this transaction as Missing.
You are now ready to do a new interest fixing.
Please note, if transaction is "Locked" (i.e exported in accounting and/or sent in payments) then transaction need to be un-locked first.
Also see instructions how you can Undo interest fixing in the Deal registration window in Front Office > Deal registration > in tab Transactions: