Network Diagnostics won't close or force quit

Well, next time I have to open the Diagnostics app again to battle with my continual lagging/dropped connections, I'll try that but I still don't see why it's suddenly started appearing multiple times when it never used to; and why you can't force quit it using any other other methods, and indeed, why you can't restart the computer and instead have to resort to a hard reboot.

...it's like the newly-insistent app is somehow not allowing the computer to restart normally, or shut the app down normally - just in the last few weeks or so. Even if I have suddenly developed the habit of not shutting the window down properly (although as usual, I simply click 'done' when it tells me my connection seems to working normally), then why can't I use any of the normal methods to shut these extra windows down?

Hi there, thank you for your ideas thus far - but I've reset the NVRAM and SMC and the computer still: a) won't quit Network Diagnostics and b) won't let me shut down via the main normal menu; I have to do a 'hard' shut-down every time now. Please do you have any more ideas?

Regards, Kate

Hi, thanks for this. Unfortunately, I have tried all of these measures. And now, even if I don't open Network Diagnostics, I can not ever get the computer to shut down via the menu; it freezes on a blank desktop with mouse pointer visible, and I have to hard-reboot by holding down the on button.

In case you have installed anti virus , or a third party software / app it should be removed . sometimes if applications are corrupted or not responding it is advised to do a fresh installation. but before doing the user must take back up of all data

I have the same problem and I have spent two days following this thread to try all suggested measures but still it is not working. I know why it freezes and does not shutdown because it is happening to me too --Finder App is not responding. I hope there is someone out there knowing what happened to ElCaptain...

I have also just started getting this issue - wifi on ipad is fine but internet hardwired or wi-fi is crippled on imac - starting in safe mode helps but only marginal. Not had time to do a full check over yet will try this evening and post any positive results.

This issue occurs on my 2016 MacBook Pro as well. It's ridiculous that this is an issue.

I was able to get it to close by opening terminal and issuing the following command:

sudo killall wdhelper

After a few seconds, the Network Diagnostic window will allow you to click "done."

Articles are there it might help : https://www.tekrevue.com/tip/how-to-force-quit-mac-os-x/

Force an app to close on your Mac - Apple Support

Startup Issues - Resolve

Startup Issues - Resolve (2)

Startup Issues - Resolve (3)

I am able to close network diagnostics tool using key board short cut : command + tab + Q selecting first diagnostic tool then , second and so on ..follow key board short cut : Mac keyboard shortcuts - Apple Support

Hi peam33

I'm having the same exact problem, and my iMac just stopped working and restarted by it self. I'm very disappointed.

Did you figure out how to fix the problem ??