When you have multiple Dynamic Web TWAIN Mac Plug-ins in the scan page, only 1 plug-in works. The others don’t work.
When you open the scan page in multiple tabs, only the plug-in in the first tab works.
The Data Source Manager is occupied by the first plug-in.
In your application, call OpenSourceManager at the beginning of every operation (e.g. Acquire, Upload, Save…), and call CloseSourceManager when the operation is done (Normally in OnPostAllTransfer Event).
In this way, the current Dynamic Web TWAIN Plug-in will release the Data Source Manager and the other plug-ins (in the same page or in other tabs) can then use the same way to open and close Data Source Manager.