Why do I get 80040e09 errors?

If you are developing with MS Access, you've almost certainly seen this error message before: 
 

Microsoft OLE DB Provider for ODBC Drivers error '80040e09'  or  Microsoft JET Database Engine error '80040e09'

 
There are many different error messages that can go along with this. 
 

Record(s) cannot be read; no read permission on '<table name>'.    or    Cannot update. Database or object is read-only.

 
Make sure IUSR has access to the database (for more information, see Article #2062). 
 
With SQL Server, the error message might be a little bit different: 
 

[Microsoft][ODBC SQL Server Driver][SQL Server]  EXECUTE permission denied on object '<proc name>', database '<database name>', owner '<owner name>'.

 
...but again, make sure the user you're connecting as has appropriate access to the table, stored procedure or any other object you are attempting to access. 
 
Another possible problem could be trying to issue an Update or Resync command on an ADODB.Recordset object based on a SQL Server view: 
 

[Microsoft][ODBC SQL Server Driver][SQL Server]  SELECT permission denied on object '<table name>', database '<database name>', owner '<owner name>'.

 
See KB #253673 for information on resolving this issue. 
 
Some databases will toss this error if you put quoted identifiers around table or column names, e.g.  
 

SELECT column FROM table WHERE 'column_name'=1

 
Quotes are for string literals, not object names. 
 
With MySQL, this error can come up if you have a malformed SQL statement. 
 

Microsoft OLE DB Provider for ODBC Drivers error '80040e09'  [TCX][MyODBC]You have an error in your SQL syntax near '<something>' at line 1

 
Can't offer much here, except to debug your SQL statement (see Article #2145) and make sure its format is correct.