I can’t remember having seen this notification before, but currently I am getting many (sometimes even multiple together) while uploading my images from my Android phone.
Also, the upload process is terribly slow.
Is anybody else seeing this?
HI
I do see them, to. thats the new uploader in the beta version (IMHO only beta). Mapillary does know and work on it.
Ah of course, I forgot I’m in the beta program, and I see an update is available, with fixes to the upload process. 
We’ll see how it goes now.