Troubleshooting “Failed to Reconnect to License Server” Error

📌 Problem

While working in LP360, the user encounters a warning message stating, "LP360 License Server: After three unsuccessful attempts to reconnect to the license server, this instance of LP360 has been downgraded to Viewer mode. LP360 will keep trying to reconnect license server. On successful reconnect, it will be upgraded back to original license" or an error message that "LP360 License Server: Failed to Reconnect to License Server".

Figure 1: Warning: After three unsuccessful attempts... will keep trying to reconnect

Figure 2: Error: Failed to Reconnect to License Server

🔍 Root Cause

This warning (Figure 1) typically occurs if LP360 cannot communicate with the license server and cannot validate the license status. This error (Figure 2) follows unsuccessful attempts to reconnect and is related to the inability of LP360 to validate the license due to connectivity or security restrictions. Following the error, LP360 will revert to a Viewer license. Addressing the probable resolutions below should resolve the issue and restore full functionality to the LP360 features.

✅ Probable Resolutions

1. Check Internet Connection

   • Ensure your computer has a stable internet connection. Loss of connectivity will prevent access to the floating license and trigger this warning or error.
   • Starting in v2025.2, a user may manually retry to reconnect to the previously used license by selecting yes on the updated warning message (Figure 1) after restoring the internet connection.

2. Review Power Settings

   • If your machine enters sleep or hibernates, the license is automatically returned, which can cause this warning message to appear.
   • Starting in v2025.2, a user may manually retry to reconnect to the previously used license by selecting yes on the updated warning message (Figure 1) after waking the computer.

3. Check Antivirus and Firewall Settings

   • If you have internet access but LP360 still cannot communicate with the server, your antivirus or firewall may be blocking the connection. Set up proper exceptions for LP360 in your security software.
   • Whitelist LP360 desktop, LP360 Online, and its license manager in your security software.

4. Consider using the https version of your License String

   • When using a Perpetual License String some unknown interference from your IT infrastructure may be causing interference with the normal communication for the license. Change the port found in your Perpetual License String from port=5053 to port=443.
   • Note: Roaming and node-locked licenses do not work with the https version of the License String.

5. Update or Reinstall LP360

   • Make sure you're on the latest stable version.
   • If issues persist, try a clean reinstall using the LP360 Installers.

6. Consider Temporarily Roaming the License

   • Roaming the license allows LP360 to operate without needing to communicate with the server for a period of time.
   • Note: A roamed perpetual license cannot be recovered if the machine fails or the license is lost.