Updating an old Unifi system

[Jobos]

I am looking to update our Unifi wifi which hasn't been updated in a very long time. The APs are AC-PRO running 4.0.54.10625, the controller is running 5.4.16 and 32bit Java 8.201 installed on the VM. The current controller release is 5.12.16.

 

Is there anything I should look out for when upgrading or to upgrade in a certain way?

 

Thanks in advance.

[BKGarry]

Take a backup, cannot stress that enough (if you are using HyperV, make a checkpoint)

 

Make sure you have the specific version of Java on the Unifi Website (it may be the version you are using)

 

Try Upgrading it, it should work.