Photoshop CC 2019 Error reading machine specific preferences

Since installing the Photoshop CC 2019 update, I get this message each time I open Photoshop:

Error reading machine specific preferences. They will be reset to defaults.

And, indeed, my preferences are reset. I saw another poster ask this question last year; the answer he/she got was to reset his/her PS preferences and disable to error messages. I followed those steps, but the error message plus preferences-reset continues to happen each time I open PS. Does anybody have any other ideas for a fix?