Fonts changing randomly

Today I noticed that the fonts on our site ( have randomly changed overnight to a variety of different serif and sans-serif fonts. This is the second time this has happened in the last year, and it takes quite a bit of effort to straighten everything back out. Can we look into why this is happening and prevent it in the future? Is there a way that you can fix it systematically, or am I going to need to open every text widget and set the fonts again? I see older topics bringing this up that were marked as 'solved', but it obviously has not been.
1 person has
this problem