Yesterday something happened to my e-mail account.  The layout of my e-mail changed. I am not sure how to describe it. Maybe the best way I can describe it is that I lost the HTML look, or layout. 

I am running Firefox. I just checked and it is version 38.0.1, and it says it is up-to-date.  I use a laptop with Windows 8.1, if that makes any difference. 

I e-mail tech support at my ISP. They recently updated their website, and they said nothing they did would have changed my e-mail. 

Can anyone provide any ideas what happened, or what I can do to get back my previous layout ? 

TIA.