When you go to Create → Decals → Choose File → Upload, it successfully uploads the Decal however it fails to add it to your Decals List. However, when you go to your Inventory → Decals, it appears there and when you go to Roblox Studio, View → Toolbox → My Images, it appears there too.
The bug specifically happens on the Create → Decals
The bug started happening yesterday around 8 PM, however, checking other development servers, developers have been saying that their Decals haven’t appeared at all.
Video here shows when you upload the Decal, it tells you it uploaded successfully, and generates its own link however it doesn’t get added to your list: https://gyazo.com/a4fb5d548286f71a325b312310837710 Look at the ruby
Screenshot here showing that it appears in your Inventory Decals, also as you noticed, that the 7 Decals next to the ruby never appeared on the Decal List (see the first video) https://gyazo.com/41c16a7eab9b8cc0afb69ea30b512db6
Screenshot here showing that it appears in Roblox Studio’s My Images, also as you noticed, that the 7 Decals next to the ruby never appeared on the Decal List (see the first video) https://gyazo.com/311384ec321a3a434fc83aba54d9846b
Update: All the existing Decals finally loaded after I’d say around 5 hours, however, if you upload a new one, it will successfully tell you that you generated a Decal but it won’t be added to the Decal List instantly (like always).
I noticed the same behavior two days ago on Tuesday. If you use create.roblox.com the decals don’t appear there either, but the associated image assets do after some unreasonable delay. The decals did show up eventually a long time after the images themselves did. It looks like the whole process has just dramatically slowed down.
This totally stopped me from working on icons for some tools because I could only get the uploaded IDs via devtools. That still happened immediately, but nothing showed up in lists until much later.
Actually I just checked and it looks like this is no longer happening, but I do occasionally get HTTP 400 when I try to upload via the create page despite the upload succeeding. This may be a separate issue.