by AL Rachels.
Hi Alex,
I seem to be having pretty much the same problem. I am using Moodle 3.1 on Centos 6.7 with MySql and I DO have unoconv installed. Typing convert commands into a terminal windows does work and makes beautiful pdf files.
When I go to grade a students online text, I do see a message in the annotation screen saying, Generating the PDF..., but nothing ever appears, just blank white space with scroll bars. If students upload a document file, I get the same results. If they upload a PDF file I can see that in the annotation window, mark on it, save it, and the students can see the result.
The path to unoconv is set correctly and clicking, Test unoconv path, reports, The unoconv path appears to be properly configured. However, when I click on, Download the converted pdf test file, which at first will try to open directly in Firefox, it is empty. Also, the document properties for the pdf is empty. If I go ahead and download the pdf file, then try to open it, Acrobat Reader reports, Adobe Acrobat Reader DC could not open 'document.pdf' because it is either not a supported file type or because the file has been damaged (for example, it was sent as an email attachment and wasn't correctly decoded).
I am stuck on what I need to try next. Does anyone have any ideas?