Selected table “wp_revslider_backup…(80MB)” returns with error

Hi everyone,

First of all congrats to the creators of this great plugin.
I am running a revolution slider based website.
Recently, I was about to implement SSL and wanted to rename all items in my library from https:// to //.
As the plugin went through all items in the tables and successfully changed the URLs, the “wp_revslider_backup…(80MB)” one returned with error message after each step I have taken and listed here below:

1., decreasing package sizes
2., increasing php memory to 256MB
3., browising this forum and trying a few ideas

Looking at the page source the pages are still coming up with mixed contents so the website is clearly suffering to load some items from a secure server. I am aware of the possibility that sorting this problem out itself will not surely solve all website issues, but I wanted to give a try to ask the community if you can come with any bright ideas before taking it to the next level?

My question is, how can I make the plugin to implement the required changes in the table suggested above?

Thank you

The page I need help with: [log in to see the link]