You cannot use "; the file is in use. Microsoft Jet Database Engine

Error Type:
Microsoft Jet Database Engine (0x80004005)
You cannot use ''; the file is already in use.

Cause of error: solution: IIS users have insufficient permissions on the data directory, and LDB files cannot be automatically generated.

Solution: add an anonymous Internet user's write permission to the data directory.

Exception details: system. Data. oledb. oledbexception: you cannot use ''. The file is in use.

This usually occurs on websites.ProgramWhen accessing the database.
There are three possible causes for this error:
1. If the IIS user has insufficient permissions on the data directory, the LDB file cannot be automatically generated.
2. The database to be connected has been opened and occupied! Closing the database can solve the problem! (Maybe someone else is downloading your database !)
3. VM users, the space is full and the purchased space is used up.
Solution:
1. in the first case, contact the space provider for the purchased space. If you are a Space Provider or server administrator, the IIS user does not have the read/write permission on the database directory. The specific solution is as follows: open "my computer", find the directory where the program is located (for example, D: \ wwwroot \), right-click the directory, select the "Security" menu item, and select "user ", add the read and write permissions of everyone users. After you confirm, refresh the browser page to use the system correctly.
2. If the problem persists, the Space Provider or server administrator can restart the server. In this way, the occupied database can be released. For VM space, contact the space provider for processing. Check whether you are uploading or downloading the database, and the database file is occupied.
3. If the space is insufficient, contact the Space Provider to increase the website space or upgrade the configuration.

Other references:
----------------------
[Analysis]
1. Solution: IIS users do not have sufficient permissions on the data directory, and LDB files cannot be automatically generated. Add Internet anonymous users to write permissions on the data directory.
Result: No.
2. log out of your Windows Account and log in again.
Result: The MDB file is occupied by a process.
Note: To determine whether an MDB file is occupied by the process, check whether there is an LDB file with the same name in the same directory. If yes, it is occupied. When the file is released, the LDB file disappears.
----------------------
Problem: cannot use "; file is in use, Microsoft Jet Database Engine
Solution: IIS users do not have sufficient permissions on the data directory, and LDB files cannot be automatically generated. Add Internet anonymous users to write permissions on the data directory.

See: Microsoft support --- Microsoft Knowledge Base Article-289681