Symnivo - all images missing and odd code appearing

Can anyone help please? I have to update a site I’ve not touched for a bout 4 years - it has 72 slideshow pages, all of the using the Symnivo plugin. However, the images are all missing (I had a mac crash a few years ago).
I am resigned to replacing each and every image manually, and adding the captions for each. BUT the first slider I’ve started on has the images sliced and show part of the next image and there is code appearing on the images. (title=*(null)"/> etc
I am using an old version of Theme ‘Media 1.3’ and the pages are ‘Blocks’.

Has anyone experienced this and can advise how to resolve? I know the developer has moved away from RapidWeaver now. Fortunately, the site is still up and running - but I need to make a load of edits before I can replace this:

TWO: I may have to use a different slideshow plunging - I need one that can feature captions for each image and is easy to rearrange image order. I will create new pages in Stacks 2.

Thank you in advance!!

If you’re using Media as a theme, why not have a look at Freestyle 2 for your slideshow? It’s from the same developer, supports captions, warehoused images - so it’s easy to move slides around - and could well do the trick.