@Crazyksparkles I am experiencing the same thing. I'm trying to do my shipping notifications and can't get to Shop Manager. These are the kinds of things etsy SHOULD be working on rather than telling us how to price our things. Perhaps some regular maintenance would avoid all of these glitches.
Mine is back but I could only get two orders up at a time to mark shipped! Every time I went back, two more were there, so it took me a few minutes to get them all marked shipped!
In another thread a seller shared they spoke with Etsy chat. They were told this issue should be resolved within 24 hours. My shop just appeared again so they are absolutely working on the problem. But I wasn't able to mark my orders as completed with tracking yet. When a resolution takes place sellers will likely be notified in the post shared by Etsy staff in the Technical Issues section.
