The first place to look when diagnosing a problem with accessing the Harweb home page is the Tomcat log files. If you're running Tomcat as a service look in the most recent %CATALINAHOME%\log\catalina*.log. If you're running it from a command prompt with the "startup.bat" file look in the console window. You're looking for any lines that begin with "SEVERE", "ERROR", "WARNING", or any Java stack traces. These will usually help provide more information about the problem.
Something you should check on is to be sure your installations of Java, Tomcat, SCM Client (and Oracle client if your database is Oracle) are at the same bit-level. They all should be 32-bit or all should be 64-bit. You can check the bit-level of Tomcat with this command "%CATALINAHOME%\version", and the bit-level of Java with "java -version". The bit-level for SCM Client can be found in Control Panel -> Programs.
If you have a specific error message from the log file that you need help solving, please go ahead and open up a new case on the http://support.ca.com website and we can take a closer look at the problem.
Let me know if this makes sense and if you need further help.
Thanks,
Melinda Skelton
CA Technologies Support Team