I ran into the same eclipse issue that I downloaded from https://www.eclipse.org/downloads/ . But I search and spend time, but the only solution I found is to " download eclipse from oracle site ". Oracle offers eclipse for development purposes. If you can download it, you can find it here .
The adapter is enabled by default in this eclipse. It has the latest weblogic server adapter. You just download it and configure your existing workspace and path to the Serer domain. It will work just like a normal eclipse.
Hope this solves your problem.