If you are using an online rule list and/or PAC scripts that are updated from a given URL, then the option sets the frequency for SwitchyOmega to download those. If you've never used those, you can safely ignore that option.
I find this plugin very useful and works really well. But for some reason, after the latest FF 57 build 10 update, the add -on does not seem to load. If I look at my list of plugins on the menu bar, I see a Loading... message for Proxy SwtichyOmega.
Try right-clicking on the icon and select "report issue" from the menu. It will open a form with error messages, which would be very helpful to locate the problem. Or, you can select "Save error log" and upload the log there or anywhere you like and then paste the link here.
Oops. I'm sorry to hear that. If that happens again, could you please right click on the extension icon and select "Report issues", which would at least capture a stack trace of why that happened? You can also click on "save error log" and attach the error log to the issue report. Please remember to do these things immediately after it happens though, since logs will get cleared on Firefox restart.