This is an issue I have seen a few times. You go to depreciate in Dynamics GP and you see that the Depreciate button is greyed out and the book is already in the Selected Books section:
Cause: After some testing I found that there is a table where the Fixed Assets module temporarily records depreciate activity for users until the depreciation process is complete. This means that once the depreciate process is done, there should be no records in this temporary table. I am usually able to confirm with a user that there was an interruption or depreciate got stuck the last time they tried depreciating.
Resolution: This temporary table is the FA40203. You first need to get connected up to your SQL server and SQL Management Studio. Then run the following script against the company database:
Select * from FA40203
There is a USERID (User ID) column in that table so look for the user that is experiencing the issue and delete that record by DEX_ROW_ID (last column in the table):
Delete FA40203 where DEX_ROW_ID = xxx
If you do not know which user it is and there are multiple records, a simpler way is to have all users exit GP; then this table should be blank. Once all users exit GP run a delete statement on the table:
This will remove all stranded records in the table and now when the user logs back into GP they will see the Depreciate button is no longer greyed out.