If you enter in a "bad" installation directory for the TC server, then it is difficult to recover from that.
Steps to reproduce:
0. Launch Eclipse with a clean workspace.
1. Go to the Servers view.
2. Right click and select New->Server
3. Select Spring Source->SpringSource tc Server v2.1 from the tree of possible servers.
4. Press the Next button.
5. Specify an installation directory which is good enough to pass a quick check but bad enough to be wrong later (e.g. plugins/com.springsource.sts.server.tc.tests/testdata/tc-server-developer-2.1.0.RELEASE).
6. Click Finish.
7. Run that server (which is wrong, a) because the directory has the wrong contents and b) because the instance wasn't created); get error messages.
8. Go to the Servers view.
9. Right click and select New->Server
10. Select Spring Source->SpringSource tc Server v2.1 from the tree of possible servers.
11. Select Next.
At this point, you can't see that there was a problem with the directory, nor how to fix the directory. Yes, on the previous page, there was a note about "Configure runtime environments", but not on this page.