Installed the free version, worked well. Needed the captions so bought and installed the PRO version. Resulted in "fatal error" crash of site.
Unintalled both versions.
Reinstalled pro. Site remained stable but slide show does not work. Thumbnails and captions show. Clicking on each image only shows that image on a plain white background.
Any help would be appreciated.

Hi there!

A tip! Need to be installed only one SIG ( free or pro ) to work in a site!
If you have both installed, the site will be crashed as you saw!

Can you please give as a link to see "live" this issue?
Try to change the popup engine to "Lytebox" and give a try to see if work now!

Thank you!