hello,
I discovered that if I updated plugin to 2.7.0 version, then customizer was not loading anymore (got just grey window), after rolling back to 2.6.9 it works well. using latest wordpress 4.9.6 and theme and child theme of Unite by Colorlib. I can go with the previous version but maybe it is something to have a look on for plugin autho
Thanks for letting us know about this Sandras. We’ve found a fix to this issue and will get it out after a little more testing. Sorry about that!