If the database is not accessible during the uninstall attempt, the program will fail to uninstall as it is unable to validate its' installation state. Confirm that the database is running, and is not blocked by any firewalls, security programs, or network gaps. Once the database is made available, the uninstaller should proceed as expected.
The use of uninstall.bat is intended for silent uninstallation of the JasperReports Server program. If you wish to uninstall the program with a GUI that provides additional information, it is recommended to uninstall the program using the Uninstall button in the Windows Programs and Features list (appwiz.cpl).
If uninstall.bat is still unable to proceed after verifying that the database is accessible, please contact CA Support for further assistance.