In case you’re also experiencing where your Repository Navigator is not dock or attached and it seems just floating within Workflow Manager like the screenshot below:
If you’re problem is the same as mine then you could try this solution to have it back on the dock. There are other cases where the issue above requires a fix on registry.
Now, just try this first if it works. Go to the white space area inside the Repository Navigator window. Right click anywhere within that white space and make sure “Allow Docking” is checked (red box). After that, double-click the title bar of the Repository Navigator window (yellow box). After that, the Repository Navigator window should go back attached again to your main Workflow Manager window.