We have an app for managing bus & truck fleets that has a module for importing fuel data from text files supplied by the fuel distributor. Since every distributor sends their data in a different format this module uses an Access database to handle the mapping of data from those text files to our app's fuel tables in SQL server. Everything works as it should except for one client...

After a recent update to the program (the only change to the fuel import module was an updated Access DB that adds two new fuel distributors) this client is suddenly getting an error when the app tries to connect to the Access DB:

"Format of the initialization string does not conform to specification starting at index 0."

There's nothing wrong with the connection string. It was never changed from the previous version.

Code:
Provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:\Dev\FleetRunner4_0_103\bin\ImportRoutines.mdb;
We have dozens of copies of this software running and this client is the only one having this issue. I noticed during a Webex session yesterday their copy of the Access DB was out of date. So I tried copying in the latest version only to get an "Access Denied" message. This company has rather tight security so I had to have the client log in as an administrator to copy the file.

I originally thought the error was due to a lack of write permissions on the program folder but he's still getting the same error even while logged in as an admin.

This has me stumped. Anyone out there ever come across something like this?