Traces are missing in the Investigator for the Java agent.
Follow these steps to typically resolve this problem:
1. Stop the EM
2. Navigate to EM_HOME\traces\index folder or equivalent.
Delete the files inside index folder
3. Go to EM_HOME\tools
Run IndexRebuilder.bat or IndexRebuilder.sh. An example is below:
C:\> IndexRebuilder.bat ..\traces
Note: While running this, the EM should not be running
4. Restart the EM