If you have ever happen to display QZ Tray Invalid Signature error message on your shipment try to follow these simple steps! 🔎
As a first thing, verify if your Antivirus is active, if so, disable it to proceed with the set up.

Check also if your Carriers have printer options set on ZPL / Zebra.

Then Uninstall and Install QZ Tray again by clicking on Print > Print on Zebra

For more information about ZPL printing take a look at the guide below:
If nothing above seems to work, try to also:
Clear your browser cache multiple times
Access from Google Chrome incognito mode
Delete QZ Tray and install it again, if Chrome still doesn't work, try running it on Firefox
Try to use Printnode instead
🔎 Do you need further help?
💬 Open a chat with us by clicking on the chat logo on the right bottom of this page or write an email to [email protected]
And you're done! 🎈