Reports builder has encountered a problem ...

1. In HKLM\SOFTWARE\ORACLE\\ Try setting your NLS_LANG setting in the registry to AMERICAN_AMERICA.WE8ISO8859P1
2. Check REPORTS_CLASSPATH in registry. Make sure it clear
3. Check you path settings
4. In $OH\bin there is a file called oracle.key. Open it and see the entry there. The entry there should match the oracle home in registry ( HKLM\SOFTWARE\ORACLE\ )
5. See whether there is any XML syntax error in $OH\reports\conf\rwbuilder.conf. Best way would be to delete the existing rwbuilder config file and start the builder. It would generate a new config file.
6. See whether REPORTS_TMP points to a valid directory.