PDF is no longer a single format. You have to specify what type of PDF. Many will not open in anything but Acrobat.
For example the Wisconsin state dept. of natural resources converted nearly all of their permit/form PDFs to "Dynamic XFA (XML Form Architecture) PDF". Which is basically a PDF without content that pulls down all it's content from the web. It even still, ostensibly, supports Flash (swf) animations. But when I try to open those permit form PDFs in any other viewer but Acrobat I get,
>"Please wait... If this message is not eventually replaced by the proper contents of the document, your PDF viewer may not be able to display this type of document. You can upgrade to the latest version of Adobe Reader for Windows®, Mac, or Linux® by visiting http://www.adobe.com/go/reader_download. For more assistance with Adobe Reader visit http://www.adobe.com/go/acrreader. Windows is either a registered trademark or a trademark of Microsoft Corporation in the United States and/or other countries. Mac is a trademark of Apple Inc., registered in the United States and other countries. Linux is the registered trademark of Linus Torvalds in the U.S. and other countries." - https://dnr.wi.gov/files/PDF/forms/9400/9400-280.pdf
PDF is supposed to be the format that looks the same everywhere all the time. But these "PDF" completely and miserably fail at that.
Thank you for giving the specific name ("Dynamic XFA (XML Form Architecture)") to the kind of PDF that generates the "Please wait" message. I have seen this and never understood how it arises. Chuck Geschke spins in his grave ...
That would be one of the reasons I’d have a dedicated computer that I power on for these kinds of things. Better than suffer bad software all the times.
For example the Wisconsin state dept. of natural resources converted nearly all of their permit/form PDFs to "Dynamic XFA (XML Form Architecture) PDF". Which is basically a PDF without content that pulls down all it's content from the web. It even still, ostensibly, supports Flash (swf) animations. But when I try to open those permit form PDFs in any other viewer but Acrobat I get,
>"Please wait... If this message is not eventually replaced by the proper contents of the document, your PDF viewer may not be able to display this type of document. You can upgrade to the latest version of Adobe Reader for Windows®, Mac, or Linux® by visiting http://www.adobe.com/go/reader_download. For more assistance with Adobe Reader visit http://www.adobe.com/go/acrreader. Windows is either a registered trademark or a trademark of Microsoft Corporation in the United States and/or other countries. Mac is a trademark of Apple Inc., registered in the United States and other countries. Linux is the registered trademark of Linus Torvalds in the U.S. and other countries." - https://dnr.wi.gov/files/PDF/forms/9400/9400-280.pdf
PDF is supposed to be the format that looks the same everywhere all the time. But these "PDF" completely and miserably fail at that.