In MS Access, sometimes you can get a Write Conflict when trying to update a table that is linked to SQL Server. Following is two suggestions on how to resolve the issue.

1. If the SQL Server table has a bit column, then set a default of 0 or 1 and then do not allow NULLS.

2. If the Table has a nvarchar(MAX) or very large field like nvarchar(4000) then try adding a column of datatype "timestamp".