Problem

I want to upload something to my Studio but I get a red crossed out circle as a result. My upload can’t be found on the exchange afterwards.
The Launcher says my upload was successful but the I can’t find it in my Studio

Suggestions

Avoid special characters in your upload names (colon, semicolon, dots, dashes, ..)
Even though you could not upload, the exchange thinks it is so you can’t upload again with the same name. Re-export your lot and use a new name.Vermeide Namen mit Sonderzeichen (Komma, Strichpunkt, Punkt, Schrägstrich, etc).
Try to re-install it to see if that works and then re-export.
If the file is big, it could be a time-out. Reduce custom content to make the upload smaller
The server is overloaded. Try later.
Upload a pattern or another house to see if it’s the house or the Exchange/Account
Replace custom content objects with EA objects.
Clean out your DCBackup folder (except ccmerged.package) and re-export the house.
Make sure nothing is blocking the connection to the servers (Firewall & Antivirus(
There’s a limit on how much you can upload. If you have a lot, remove some older stuff you don’t need anymore.
Check the sims3launcherlogfile in your user data directory to check on the message.
Upload somewhere else
Make sure you’re logged in.