Operation must use an Updateable Query
I know I see this error about once a year and can never remember the cause, so I’m writing it down this time!
In my case it has always been related to SQL queries and Access databases. Check the following if your SQL command produces this error when executed:
The database is not read only - Visual Source Safe can often be a culprit in setting this property..
The SQL query may contain fields that are reserve words (e.g. DATE, TOP etc.). These should all be renamed in the database (I normally add an underscore at the end).
Go through a long and tedious process of which Windows user is running the SQL (ASPNET, IUSR_COMPUTERNAME etc.) and check thy have write permissions to the folder containing the database, and the database file itself. Remember Access needs to create those pesky .ldb lock files..