The Reservation Entry Does Not Exist

The Reservation Entry Does Not Exist 

Reservation Entries can cause a lot of issues in NAV (all version). Sometimes the Reservation Entry table can have duplicate reservations against a single item (same Source ID - Doc No.) and as a result can cause issues due to these conflicts. The most common of these is the error 'The Reservation Entry does not Exist'. Most of the time this can be easily fixed.

Typical error:

1. Open the Microsoft Navision Classic Client (with SQL if applicable).
2. Log into the Database >> Open the relevant company.
3. Ensure you are logged in as a user with adequate permissions - ie. Super.
4. Tools >> Object Designer
5. Select the Table - 'Reservation Entry' (Typically 337).
6. Run the 'Reservation Entry' table and search for the 'Document No.' in the 'Source ID' column.
Note: You should know the Document No. as this will be the document where you are getting the error. Eg. order, invoice etc. 

7. At this point the issue may differ but most of the time you are looking for duplicates. For example - if you know you have only 1 reservation against this document (with 1 item on the document) - but two are sitting in the reservation entry table, the duplicate could be causing issues. Typically I would delete all the reservations relating to this Item / Document No and re-reserve the Item.

Please do not do this unless you are confident with filtering/running tables. This is only a general guide and is meant to help you try to find the issue yourself. Deleting entries from Tables directly is EXTREMELY Dangerous and may cause irreparable damage/loss of data. - Any doubts, don't do it!