Customizer can not be accessed. Got broken


Hello! Having troubles with Jupiter X. I can not access Customizer at Jupiter X | Customize. This happened for the second time. While saving Customizer once i got an error. And now Customizer is broken. So my webpages on Front End. There has to be some bug in Customizer. Rest of the Back End is loading.
I can not import previously exported Customizer settings. I can not reset Customizer settings when it is not loading.

Could anybody help?