info_i_25x25.png See important information about Ubiquiti Devices and KRACK Vulnerability in this article. We will update this document as more information becomes available.

UniFi - Controller fails to start when opened


UniFi controller fails to start up when opened.

Possible causes / recommended actions 

Problem: Windows profile's username has special characters

1. The controller's database (mongo) will not start because it cannot find a file. 

2. The solution is to change the username and make sure it has no special characters (including accents, for example á, ë, ì, ô, ç, ã) .

Problem: One or more ports needed by UniFi are being used by other programs.

1. Take a look at <unifi_base>/logs/server.log

info_i_25x25.png Note: The location <unifi_base> will vary depending on your operating system. See this article for more information.

2. Most likely, there will be an ERROR similar to this:

[2011-06-01 22:09:14,145] <UniFi> ERROR StandardServer - StandardServer.await: create[8081]: Address already in use: JVM_Bind
 at Method)

3. Change the ports used by UniFi controller, as seen in this guide.

Problem: Java incompatibility (Javaw.exe is missing)

    1. Ensure that the correct Java version is installed on the machine (32 / 64bits).
    2. Java version should correspond to browser (Chrome is 32-bit browser).

Problem: Java incompatibility with old firmware version (2.2.5 or earlier).

    1. If using UniFi 2.2.5 or earlier, make sure that Java 6 is installed on your computer, since Java 7 is not compatible.
    2. Ensure that the correct Java version is installed on the machine (32 / 64bits).
    3. 64-bit based Windows 7 & 8 machines must use a 64-bit web browser and Java install.