Thank you for looking at this.
I have done a test: I tried to open
tm2018_en.pdf by invoking the '
Document Viewer' application, not from within TextMaker but from a Linux file manager. As you see, it failed:
All other document reader applications are able to open
tm2018_en.pdf.
Document Viewer is able to open all other PDF files.
There is evidently something in the '
Document Viewer' application that doesn't like something in the
tm2018_en.pdf file.
It would be really helpful if you could find and fix whatever it is in
tm2018_en.pdf that is causing this error, because the
Document Viewer display is very compact and neat, so it is really good for use as a small overlay window for displaying the Help file. But if other things are more pressing, this could wait.
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John