How to Fix Unifi Controller Startup Failed Issue When Opened

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Many people have reported encountering the problem of failed UniFi controller startup. Some users encountered the problem while trying to update the UniFi controller software, while others received the error after starting the software for a few minutes. So far, the error that the UniFi Controller failed to start has been reported by many Windows 10 users.

It fails with the error :

“Port 8080 is already in use by another program”

or sometimes

“Server taking too long to start…Start-up failed.”

What is the cause of the error? After reviewing many user reports, we have found several possible reasons why the UniFi controller does not boot.

  • Lack of free space on the host system disk.
  • Incompatible or obsolete JAVA installation.
  • There are special characters in the Windows profile username.
  • Required ports are not available for the UniFi controller.
  • Database corruption.
  • Damaged UniFi protocols.
  • Temporary errors in the UniFi controller software.

The above causes are used to identify appropriate solutions. Now we will see how to fix the UniFi controller boot failure.

Empty space on the system hard disk

The Unified Controller software requires additional free space on the system drive to complete its operation. This error may occur if you do not have enough free space on the system hard disk. In this context, creating free space on your hard disk may solve the problem. To illustrate this, we will discuss the process for Windows.

  • Free space on the C drive (system drive).
  • Then, run the control application if it works correctly.

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Change the engine specified in the system properties file

If the database was created by the “mmapv1” storage engine, but the specified storage engine was “wiredTiger”, this error may occur. In this context, forcing the control application to use the mmapv1 storage engine may solve the problem. As an illustration, we will discuss the process for a Windows PC.

  • Start the file explorer and navigate to the installation directory of the controller application. This is normally the case: %USERPROFILE%\ Ubiquiti UniFi\data
  • Now open the System.Properties file with the notepad and add the following line at the end of the: db.extraargs=–storageEngine=-mmapv1
  • Save your changes and exit Notepad.
  • Then start the control application and check if it works properly.

Check if the required ports are not available

The ports required by UniFi are used by other programs. Change the ports according to the steps described below.

  1. go to /logs/server.log
  2. there is a high probability that a similar ERROR will occur : address already used: JVM_Binding
    to method)
    Or :
    < Startup Program Monitor> Startup Program ERROR – Port 8080 is used by other programs
  3. Modify the ports used by the UniFi network controller.

Incompatibility with Java

Currently, Java 9 is not supported for the UniFi network controller. Please use Java 8. The controller software release notes, which can be found with the software on our download page, contain notes and requirements for each version.

Make sure that the correct version of Java is installed on your computer (64-bit). Starting with version 5.10.12 of the UniFi network controller, it is necessary to use x64-Java, as we only support the 64-bit WebRTC library. Uninstall Java, if applicable, and install Java 8.

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