"Failed to set plugin placeholders" message?
I had the same problem today. In my situation I had a different identifier in my original app than in the extension identifier "base". The extension has to have the same identifier as the original app plus something else.
- Dummy App:
- Dummy App Extension:
After Xcode told me that, I changed my wrong names to look like above and then the problem occurred:The problem was, that I had "automatic manage signing" turned
on but Xcode didn't recognize that I changed the identifier.
Solution:Just change the identifier again and check if "automatic manage signing" has created a new provisioning profile. Deleting derived data may also helps.