Starting from index 0, the format of the initialized string is invalid.

It seems that this problem occurs only when the ACCESS database is used.

The reason is that the connection statement is wrong, so"Starting from index 0, the format of the initialized string is invalid. "This error
Example of Asp.net C # below

Common error: only the database path is written

Oledbconnection hooyesconn =   New Oledbconnection (server. mappath ( " Database/hooyesdatabase. MDB " ));

Correct: You have to write Microsoft's logo.

Oledbconnection hooyesconn =   New Oledbconnection ( " Provider = Microsoft. Jet. oledb.4.0; Data Source = " + Server. mappath ( " Database/hooyesdatabase. MDB " ));

ArticleSource: http://www.hooyes.com