It looks for the eps in the directory you specify in Settings/User/PDF forms. You need to repair your installation .. use the repair button
Is there a standard .pdf format ? I have issues like some pdf forms will work with 32 bit gswin and others that work with 64 bit. I think it is safest to one use the gswin that you are using in synapse, 32 or 64 bit.
The pdf coordinate system starts at the bottom left corner of the page, which would be (0,0). The measurements are in 1/72 inch, so there are 72 points per inch. Here's a link to a webpage with more. https://stackoverflow.com/questions/30319228/where-is-the-origin-x-y-of-a-pdf-page
The PDF file format has evolved considerably since introduction of version 1 in 1984 to version 2.0 in 2017. I've used versions 1.4 to 1.7 a whole lot. If you click on file properties, it will list the version of PDF the file uses and which software created it (usually). There are also subtypes of PDF files, e.g., PDF/A which is for archiving documents and PDF-MRC (mixed raster compression) which is a superior way to compress PDF files and make them searchable (Paperport Pro 14.5 has a PDF-MRC file converter). The wikipedia article on PDF's has a pretty good summary. https://en.wikipedia.org/wiki/PDF I have sometimes had issues converting PDF's of one version or another to other PDF formats using various graphic and image conversion programs but I haven't tried it with ghostscript much. Here's an old post from the ghostscript forum about just such a bug. https://bugs.ghostscript.com/show_bug.cgi?id=689813
Yep, and Rebol uses a co-ordinate system that uses top left as 0x0 so I have to flip them in the postscript dialect I use.
I use C:\Users\anon_\OneDrive\Synapse\pdfs\ as the location for my PDF/PNG/EPS files. I didn't mention that the directory has to be below the directory in which the synapse.exe binary has been installed. It doesn't have permissions to look outside its own root directory I think.
I think gsview is offering to core dump the data for debugging. Here's an example post from the ghostscript forums of somebody using core dump to debug what went wrong with a pdf that was producing a segmentation fault/memory corruption issue. https://bugs.ghostscript.com/show_bug.cgi?id=698615
Apparently Rebol was released as open source in 2012. So, do you need a license to use something Rebol related still? The free download page is http://www.rebol.com/downloads.html.
Rebol3 was released as open source. The only existing fork of that is ren-c which I use for my day to day scripts. But Synapse EHR is based on Rebol2 and that won't be released as open source due to the wishes of the investors I believe.