Please revert to the old version by:

1. Uninstall the version you have now (type about:addons in the address type and remove FoxyProxy)
2. Install the one version from here: https://addons.mozilla.org/en-US/firefox/addon/foxyproxy-standard/versions/ you want version 4.6.5
3. Your old settings will magically reappear

This is a temporary solution--that older version will only work until November 2017 when Firefox 57 comes out. But long before that time, the new version will have evolved with more features. Note that some features are not possible anymore due to Firefox's new addon ecosystem called WebExtensions. They are much more restricted than older addons (pre Firefox-57)