Summary
The PixTWAIN driver is not supported with ScanConnect.
More Information
The PixTWAIN ISIS driver is intended to allow an ISIS application to access a scanner that only has a TWAIN driver. However, it is still using the underlying TWAIN driver.
If you want to use ScanConnect, please use the correct ISIS driver for that scanner. Otherwise, if you only have the TWAIN driver for you scanner, use the TWAIN scan engine and select the appropriate TWAIN scanner driver.