I have created a newsletter for my school using Adobe Spark. I have tried the download as pdf BETA within that app but there are issues with font spacings that aren't present in the originals.
I then downloaded PNGs to my laptop and tried to use Acrobat DC to merge them into one PDF.
The program said was converting each image in turn, but they then greyed out, with a yellow warning triangle. At the end of the process a message came up saying "No PDF was created because Adobe Acrobat encountered and unidentified error.'
Is this a known error, and are there any solutions I can use so my newsletter can get published?
Since you've exported a series of documents from Adobe Spark to a PDF, it may be possible that some of the font tpes embedded in the source document may have copyright restrictions.
This is true if, for example, the source files that you're trying to merge contain restricted fontypes (or any other element with copyright restrictions), in which case (and let's assume that would be your case) you may have to find out if the creator of such fonts requires to pay for a license in order to use it.
If you open one of those PDFs Acrobat, notice what type of fonts are used or embedded in it.
Click on "File"--->>> "Properties", and then click on the "Fonts" tab.
Right below that tab, see the section: "Fonts used in this document".
Scroll through the list of embedded fonts and look for any type of embedded subsets that may not be part of the operating sysmem's font library nor Acrobat's.
Again, It may be possible that if the embedded subsets have a copyright restriction, the merge action will stop and the distilling process will throw that message.
You can also use the Accessibility Checker tool.
When you run a full report with this tool you will get a detailed list of error founds based on failed tests.