UniFi Controller Startup Failed — Here Are Top 8 Solutions

What Causes UniFi Controller Startup Failed Error

What causes the error? After investigating many user reports, we found several possible reasons that can cause UniFi controller won’t start.

  • Lack of free space on the host system drive.
  • Incompatible or outdated JAVA installation.
  • There are special characters in the Windows Profile username.
  • The required ports are unavailable for UniFi controller.
  • Database corruption.
  • Corrupt UniFi logs.
  • Temporary UniFi controller software glitches.

According to the above causes, the corresponding solutions will be illustrated. Now, let’s see how to fix UniFi controller startup failed.

How to Fix UniFi Controller Startup Failed Error

Top 8 Solutions to Fix UniFi Controller Startup Failed

  1. End all the UniFi-related controller processes
  2. Add a new user without any special characters
  3. Extend your system drive space
  4. Change the default port for the UniFi controller
  5. Rename the UniFi Logs
  6. Change the specified storage engine
  7. Reinstall JAVA
  8. Install the UniFi controller as a service

Solution 1. End the UniFi Controller Related Processes

Now, you can launch the software and check if UniFi controller not starting. If this method fails to work, just move on to the following methods.

Solution 2. Add a New User Without Any Special Characters

If it is indeed that the special characters cause the error, you can create a new user profile without special characters. Here’s how to do that:

Step 1. Start your Windows 10 PC in Safe Mode.

Step 2. Press Win + I keys to open the Settings app and click on Accounts.

Step 4. Click on I don’t have this person’s sign-in information in the pop-up window.

Step 6. You can transfer all of your personal data to the new user profile.

After that, restart your computer and see if the UniFi controller failed to start.

Solution 3. Extend the System Drive Space

How to extend system drive without data loss? To do so, you can utilize a professional software — MiniTool Partition Wizard to extend your system drive. It is a trusted partition manager that spares no efforts to provide various solutions like space analyzer, migrate OS to SSD, recover lost data, perform a disk benchmark, etc.

Click on the buttons below to download MiniTool Partition Wizard and install it on your computer.

Step 1. Run this program to enter its main interface, and then select the system partition and click on Extend Partition from the left pane.

Step 3. Click on the Apply button to execute this operation.

Now, your system drive should have enough free space to run the UniFi controller. Also, you can utilize a Junk File Cleaner to clean up the unnecessary files to free up C drive.

Solution 4. Change the Default Port for the UniFi Controller

To do so, follow the steps below:

Step 1. Perform a clean boot to check which program causes the UniFi controller not starting error. If you don’t know how to do that, you can refer to this post. After you find the conflicting program, you can uninstall it from your computer.

Step 2. If the UniFi controller failed to start even after performing a clean boot, then you need to change the default port for the UniFi controller application.

Solution 5. Rename the UniFi Logs

Step 2. Press the Win + E keys to open the File Explorer, and then go to the UniFi controller directory folder. Usually, you can find the directory through the path: This PC > Local Disk C > Ubiquiti UniFi > logs.

Step 3. Now, you can rename these log files in the UniFi controller directory. Here you can add the .old at the end of the file name extension.

Step 4. Relaunch the software and see if the UniFi controller startup failed error is fixed or not.

Solution 6. Change the Specified Storage Engine

Step 1. Open the File Explorer, and then go to the UniFi controller directory folder.

Step 2. Find the System.Properties file and open it with the Notepad, and then add the following line to the end of the text.

db.extraargs= — storageEngine=mmapv1

Step 3. Click on File > Save in the Notepad to save the changes and exit.

Now, you can relaunch the program and check if the UniFi controller not starting issue still persists.

Solution 7. Reinstall JAVA

So, it is necessary to ensure that you have installed a correct JAVA version. Here’s how to uninstall your current JAVA and install the correct JAVA.

Step 1. Exit the UniFi controller software first and end all the UniFi-related processes in Task Manager.

Step 3. Change the View by type to Category and click on Uninstall a Program under the Programs section.

Step 4. Right-click the JAVA from the list of installed programs and click on Uninstall. Once the JAVA is uninstalled, restart your computer.

Step 5. Click here to download the right JAVA version for your Windows PC and install it. If you are prompted with a message stating Firewall to allow JAVA, allow it.

Note: You should install the 64-bit JAVA version 8 to make sure the proper operation of the UniFi controller.

Now, you can launch the UniFi controller software and see if it can start up properly.

Solution 8. Install UniFi Controller as a Service

Step 1. Close all UniFi-related processes in Task Manager.

Step 2. Add the JAVA path: C:\Program Files(x86)\Java\jre7\bin\javaw.exe in the environment variables of your Windows system (at the end of the path in the Temp variable). Then click on OK to save the changes.

Step 3. Type cmd in the search box, and then right-click the Command Prompt app and select Run as administrator.

Step 4. In the elevated command prompt, type the following commands one by one and hit Enter after each one.

  • cd “%UserProfile%\Ubiquiti UniFi\”
  • java -jar lib\ace.jar installsvc

java -jar lib\ace.jar startsvc

Now, restart the controller and check to see if the UniFi controller failed to start.

The UniFi controller startup failed error pops up when upgrading the software. I fixed the issue through the second method in the post. Are you struggling to fix the UniFi controller issue? This post shares 8 effective troubleshooting methods. Click to tweet

Bottom Line

Originally published at https://www.partitionwizard.com on October 14, 2020.



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