You can still enter or edit exchange rates for periods locked with Lock Date and make changes to the financial statements.

Fixed in the latest version (20.10.97)

This makes a lot of sense, changing the exchange rate of a locked period would throw off the opening balance sheet. I think this should be in ideas.

Extend Lock Date Control To Exchange rate Settings

Topic		Replies	Views
FX rate changes possible after entering Lock date	7	656	March 11, 2022
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Confusion on entering exchange rate	13	1856	July 28, 2021