Novice question: Will Updating Retailer Theme Lose Content?

I get a popup telling me it will, but I want to be sure I can restore backup. This is a two year old site, being revised by a couple of newbies trying to figure it out.

I can’t get a copy of the theme documentation.

When I updated the Wordpress version from 3.8 to 4.4 I lost some images and some of the short codes are not working. I think I need to update the theme, but don’t want to risk losing data…

Please help! I can’t find any tech support. This was a purchased theme. Thanks!

Ask the author here

It should not lose content BUT it really depends what has been changed, how it was setup etc. and it is hard to know what will happen without some kind of insight on this