MapDB Errors in PaperCut NG/MF

“Help! Our PaperCut NG/MF server is failing to start, and when we try to log into the browser we see an error message that mentions MapDB. What does it mean, and how can we fix it?” If you encounter this problem, you may see one of these errors when trying to access the Web Interface of your PaperCut NG/MFServer. An error occurred starting the PaperCut MF application server service. To resolve this error, try restarting the service. A detailed error log is recorded in the server log file: C:\Program Files\PaperCut MF\server\logs\server.log Error description: 0 Error details: java.lang.IndexOutOfBoundsException: 0 ... Or the error details may give one of these messages instead: java.io.IOException: Checksum does not match, data broken Error details: java.io.EOFException Errors like these typically pertain to the configuration stores that PaperCut NG/MF uses, called MapDB files. The trouble begins when the application is in the middle of writing to these files and can’t gracefully finish the operation, maybe because the server suddenly lost power or ran out of disk space. MapDB files essentially back up all the current connections PaperCut NG/MF had open at the time the service started, and thankfully, they aren’t too important, but before PaperCut NG/MF v18.3.6, when we resolved this known issue we did hear about this affecting several customers. To get this fixed and working, try the steps below: Stop the PaperCut Application Server service following these steps Navigate to [app-path]\server\event-store . If you are using an older end-of-life version of PaperCut NG/MF, you may find this instead in [app-path]\server\data\internal . Windows: C:\Program Files\PaperCut MF\server\event-store macOS/Linux: /home/papercut/server/event-store Copy all the files containing mapdb in the name to a different folder, such as the desktop. Then, delete these files from the source folder. Restart the PaperCut NG/MF Application Server service. After the restart, PaperCut NG/MF will create a new set of MapDB files, and after a moment, you should be able to log into the PaperCut NG/MF server’s web interface. If our advice doesn’t work, it might indicate a deeper database issue. In that scenario, please contact our support team directly so we can investigate. Still have questions? Let us know! We love chatting about what’s going on under the hood. Feel free to leave a comment below or visit our Support Portal for further assistance.