This situation occurs when you try to open an SQL database which was created with JabRef version older than 3.6.
With release of JabRef 3.6 the SQL database structure has changed. So all SQL databases with an pre-3.6 structure are no longer supported.
To migrate your pre-3.6 SQL database into new shared SQL database you have to follow these steps:
Download and install JabRef 3.5
Open JabRef and goto File -> Import from external SQL database
Enter required data and click on Connect
Choose the database which should be imported and press Import
Save the database locally (File -> Save database)
Turn back at least to JabRef 3.6
Goto: File -> Open shared database
Enter required data and click on Connect
Now goto File -> Import into current database
Choose the file you saved locally and import it
After that the content is available as a shared SQL database and you can work live on it. More information about the live editing.
