Plugin doesn’t work on my site if activated

Hi, I have CF7 and Success page redirect and CF7 skins plugins all working fine. As soon as I activate Conditional fields plugin, CF7 forms creation page tabs don’t do anything when clicked except drop to bottom of the Additional Settings box for email tab and show nothing in the Conditional Fields box. It is there, just grey with a heading
Clicking on Forms tab does this as does tab for Success page redirect. Conditional fields does the same as above, although it appears in all the right places (on menu bar, has a field (although disabled).

I use WordPress very basically and have no idea how to go about troubleshooting this. I have a load of other plugins that work fine too, but now creating forms, the Conditional Fields looks very useful and what I need.

I have disabled a lot of plugins, not all but still the same.

Appreciate any help that can be given