Hello Oli,
I found the following hint on LCS:
A wizard was added under Fixed assets - Setup to add the reporting currency amounts on posted transactions. This must be completed before new depreciation transactions can be entered. In order to know this is complete, the user must change the flag to Yes on the last page of the wizard. Even after changing that flag, the depreciation and acquisition proposals could not be completed. This happens only if the wizard is previously finished with the flag set to No and then run again and changed to Yes.
Solution:
To work around this until a hotfix is available, do the following:
1 - Go to User options - Usage data button and select the All usage data table of contents. Find AssetReportingCurrencyAmountsController and remove this record.
2 - After this record is removed, please run the 'Add reporting currency amounts to fixed asset books' wizard again. Make sure that you select Yes option on Finish reporting currency update page.
3 - Now you should be able to run depreciation or acquisition proposal.
Can you try this?
Best regards,
Ludwig