This issue might be related to your session information that is expired. Clearing the app cache should fix the issue.
If you’re running on the Windows app, you can clear the app cache from the “Help > Reset Zeplin” menu up top, then relaunch the Windows app.
If this does not work for you, you can follow the steps below:
Uninstall the Zeplin Windows app
Delete the folder named Zeplin in the revealed Explorer window
Reinstall the Zeplin Windows app via https://zpl.io/download
To clear the Zeplin Mac app cache:
Log out using the profile menu on the top
Quit the Zeplin Mac app
Open Finder and select "Go > Go to Folder..." from the menu up top
Type ~/Library/Caches and click Go
Delete the folder named io.zeplin.osx in the revealed finder window.
After clearing the app cache, give it another try. If the issue happens again, you can contact us at firstname.lastname@example.org.