Apple is moving to obsolete 32-bit support in its macOS products, beginning with High Sierra 10.13.4. TWAIN Application and Driver writers should transition their macOS products to 64-bit. The open source Data Source Manager (currently at version 2.4.2) provided by the TWAIN Working Group is a universal binary that includes 64-bit support. For more information about Apple’s plans, please look here: more information from Apple