Java Plug-in 1.5.0 is not supported. What you need to do is remove all Java VMs from your machine, then access Topology Services again. This will download and install the one supported Java Plug-in from the CiscoWorks server. Depending on your version of LMS, this may even contain the vbjorb.jar file (if you have LMS 2.6). Once you've done that, then Topology Services will work.
Note: currently the supported Java Plug-in version is 1.4.2_10 without the recent Daylight Savings Time patch for the U.S. and 1.4.2_12 with said patch.