I got a new Firefox update a few weeks ago and the only problem was it blocked the uBlock origin ad blocking program I've been using and I had to download it again. I did notice I get a message on Win10 when I get updates that it wants me to change my search engine from Firefox to MS Edge but I just ignore it.
What OS are you using? My boyfriend heard rumors that Windows 10 is changing their safety features and that may impact the use of Firefox, Safari and other search engines.