Why did my sync between Lightroom Classic and Smugmug fail, after working OK a couple days ago?

ronshrieves

I have just began to use Lightroom Classic (LrC). I had been using Aperture for post-processing (for many years) prior to my subscription to Lightroom. I have also had a Smugmug account for years. Naturally, I desired to use Lightroom to "Publish" my photos to Smugmug from Lightroom Classic. I had succeeded in syncing a prior version of my Lightroom catalog with the Smugmug account. I believe that was done with version 10.3 of Lightroon Classic. I had lost a substantial amount of my keyword data in the migration. After "cleaning up" my rather messy Aperture library, I successly migrated my Aperture photos into Lightroom, with all keywords. My Lightroom version was upgraded automatically in the last couple of days. I don't know exactly when, but I think it was today. Yesterday I created a newer version of my Lightroom catalog. Today, while using Lightroom 10.4 in an attempt attempt to sync to the newer lightroom catalog, syncing started working, but was quickly halted after only a few photos were synced. The message I got was "An internal error has occured. ?:0:attempt to compare string with number." I suspect that the error was due more to Lightroom upgrade rather than changes in the Lightroom catalog, but I can't be sure. (I had already trashed the old catalog.)