Can't upload new activities

I've tried upload my new activities using garmin express but it is not uploading.

same problem with Edge 800 today. 3 days ago, all was normal.

Same problem with my 910xt. Looks like the data is transferring from the watch to C:\ProgramData\Garmin\Core Update Service\Sync\<device id>\Upload\FIT_TYPE_4, but it doesn't get uploaded to connect or moved to C:\ProgramData\Garmin\GarminConnect\Forerunner 910XT-<device id>\Upload\FIT_TYPE_4

410 with upload issues as well
Express says everything synced successfully but no updated data is in either C:\ProgramData\Garmin\Core Update Service\Sync or C:\ProgramData\Garmin\GarminConnect\Forerunner 410-<device id>\Upload\FitnessHistory

I tried the usual steps (reset, reinstall, reboot) with no luck. This is happening with more and more frequency and is getting really frustrating.

When I try to manually add the activity, I get "You have entered a value that is not accepted by the database. Please enter a new value." With no indication of which field has an issue. Of course not.

I love the hardware but the software is in seriously sad shape.

Same here, with my forerunner 620. I installed a plug-in twice (removing the first one in between). Nothing works. Everything was a-ok just a week ago...hmm

Same here - Forerunner 10 won't upload Saturday's run. Been fine up to now. Could this be to do with the website perhaps?

I am having the same problem on my 620. Did the upload via wireless, and got the message transfer complete. But not showing on activity online. Tried syncing via garmen express and it show todays filw waiting to sync, but on symcing get message Sorry, we couldn, t sync your device. Please try again.

I'm having the same problem with both a 620 and a 910. I tried removing the device completely and re-adding it, but that didn't do anything. In fact somehow in the process I lost all data on the 620.
PLEASE FIX

Same problem here (Edge 810) uploaded OK last night, this mornings ride home from work won't upload to Garmin Connect but uploaded to Strava fine.
My Vivofit uploaded to Garmin Connect OK.