Custom Dashboard is not loading after making changes in variables

I have a custom dashboard for which when i made changes in variable, it has stopped loading. On loading the page it says “Services” and stuck at this state. Kindly help me out to recover this dashboard or any other way to rectify the changes made in variables. If there is any way i could get hands on the json file of that dashboard, it will save a lot of my time. Kindly help.

Check browser console. You may see there an error, which will help you understand what is a problem with variable.

Then play with version API - and restore previous dashboard version, which was working.