Installation and Upgrade > Installation and Configuration Guide > Advanced Configurations > Running Windchill as a Windows Service > Troubleshooting Tips
  
Troubleshooting Tips
If the “JNI error finding main class” or “Unable to change the working directory” messages are displayed in the Windows Event Viewer, then try the following:
Verify your CLASSPATH settings to ensure it is correct. If a directory contains spaces, enclose the directory path in quotes.