I try to upload files in a blob container using Microsoft Azure Storage Explorer, but it is stuck in the state :
Uploading Group...
and nothing happens (no message, no error).
Until a better solution, I found a workaround: use a previous version! (0.8.16)
You can download it there: Download Azure Storage Explorer 0.8.16 (Preview)
It seems this is a regression of the v0.9. ISSUE - Storage Explorer