I recently upgraded from Mac OS High Sierra to Mojave; both of these OS versions still allow applications to run in 32-bit mode, and I was initially able to continue to use PS CS5 in 32-bit mode after the Mojave upgrade. The only reason for needing to run in 32-bit is to use the legacy TWAIN plugins to work with my CanoScan 8800F, otherwise neither Canon nor Apple still support using this scanner model in any Mac OS after Yosemite.
My problem is that I also needed to clone my system over to a different drive for capacity reasons; after this PS CS5 still worked ok, however, it defaulted back to 64-bit mode after the move to the new drive. I assume that some preferences file got reset in the process, however, the check box for 32-bit mode that used to be available in the Mac "Get Info" window has now disappeared.
To get back to 32-bit mode, I'm looking for the hidden preferences file or OS command to get PS CS5 back to the 32-bit mode ... if I can do this, I can continue to use my CanoScan 8800F. Thanks in advance for any suggestions!
If that option is no longer there, I don't know how to bring it back.
As a workaround, have you tried using the Image Capture app to scan? I'm not sure if it will work, but it's worth a try. Image Capture in an Apple app you already installed: Scan images in Image Capture on Mac
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