@DavidGeeroms 

This would be expected behavior

The controller is designed to be online 24/7 and not something you run on occasion from your home PC.  The software controller is generally run on a server / raspberry pi or OC200 which is never powered down.

So to answer your question, for the most part the APs etc will operate as normal whenever the controller goes offline (with exception of roaming, mesh etc that requires a controller online).  However when the controller reboots or powers on again it will contact the devices and re-adopt then into management, this process re-applies the configuration you set on the controller and therefore takes the device offline for a period until the process has completed.  Its expected that controller reboots are rare things.

You are not required to have a controller and can run the APs in standalone mode, which may be more suitable for you.   Or consider buying an OC200 / installing on a Raspbi Pi and running it that way

If you have a controller, it needs to be online all the time

@DavidGeeroms 

I agree with Philbert, but I don't know why you lost all connection as soon as you run the controller. Could be the issue of your topology.

And also when the pc running the controller, did it connect to your wireless network or wired to your network? I ask this just because wired to your network will give you a stable connection. Same deal when you use the controller software.

@Yannie 

When I connect to wifi and I start the controler software I lose the connection with the wifi.

@DavidGeeroms 

Hey

Is it the case that you are running the controller on the same WiFi SSID that you have configured via the controller?   I would recommend against doing this, the controller should be online constantly via a LAN cable, its not really designed to be powered down and up continuously. 

How many access point and switches do you have running?  It may be better and easier for you to not use a controller, instead setting the device for Standalone mode.