If you encounter any scanning issues using Citrix scanner redirection, it might be necessary to use the Twain 1.9 or older data source manager (twain_32.dll). By default, Tiff Viewer uses the Twain 2.0 or later data source manager (TWAINDSM.dll), which might cause some compatibility issues with older scanners, or when using Citrix scanner redirection.
The version of the TWAIN data source manager DLL can be specified in the TIFF Viewer Options:
For using Twain 1.9 on Citrix, select the Twain 1.9 or earlier option.