Everything was working fine and suddenly I am facing my MacBook is lagging and apps keep on bouncing in the dock when I try to open them.

I tried resetting SMC, NVRAM/PRAM but the problem still exists. I tried restarting shut it down for sometimes but no luck.

I turned off WiFi and everything was working fine, no lag and no freeze but as I turned WiFi on, it started lagging again.

Any ideas what's causing this issue?

  • Something is obviously happening when you connect to a network. Do you have an Ethernet adapter to connect to the network with? This will help rule out hardware vs. software. Also, boot into Safe Mode (Hold Shift while booting) to see if the problem persists. This will tell us if a 3rd party piece of sofware is being loaded that's causing the problem.
    – Allan
    Apr 21, 2020 at 21:34
  • @Allan, I don't have any Ethernet adapter connected. I boot in the safe mode for the first time, it looks like the problem persists. I am not using any third-party services which use a heavy internet bandwidth. A simple program like VLC media player is not opening on a single click, It keeps on bouncing and as I disconnects the internet it opens suddenly. Followed this thread but it didn't' worked out for me apple.stackexchange.com/questions/389062/…
    – Muhaddis
    Apr 21, 2020 at 22:38
  • I can replicate the request. I am sure this is not the problem with the hardware as if the WiFi is turned on and as long as I am not connected to the WiFi network, it works fine.
    – Muhaddis
    Apr 21, 2020 at 22:42

2 Answers 2


I figured out the problem was with my network cache. None of the online help worked for me.

The problem was occurring only for my home WiFi. I connect with the VPN and noticed everything was working smoothly as earlier.

I cleared my DNS cache, and reset the network configurations. I deleted the directory /Library/Preferences/SystemConfiguration/ and run the commands to flush the DNS cache

$ sudo dscacheutil -flushcache
$ sudo killall -HUP mDNSResponder
$ sudo killall -HUP mDNSResponder;sudo killall mDNSResponderHelper;sudo dscacheutil -flushcache

Make sure to take the backup of the SystemConfiguration just incase. Your system can generate the files later.

Hopefully, this will help anyone else who seems to be having freezing issues when connected to the internet.


This worked for me, thank you Muhaddis. Wanted to add that I also needed to disable SIP in Mojave in order to delete the SystemConfiguration folder.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .