Official Link : http://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=660&top=18
IRCC's immigration forms are XFA-based PDF forms designed in Adobe LiveCycle. These type of forms require minimum Adobe Acrobat 8 to open. Modern-day cellphone apps don't support Adobe PDF versions 8 or above.
Along with that, these PDF forms are policy-protected document which are made "Secured" using Adobe LiveCycle Rights Management.
Chrome's built-in PDF plugin cannot handle XFA-based PDF forms due to its limitations. You must use Adobe Acorbat's plugin. Follow this guide to Open these PDF files directly in Chrome using Adobe Acrobat Reader : https://helpx.adobe.com/ca/acrobat/kb/open-in-acrobat-reader-from-chrome.html
Tested on my Windows 10 PC with following:
Note1: Only Internet Explorer 11 is able to open forms correctly. It seems to be the ONLY browser using ActiveX plugin straight from Adobe Acrobat Reader's DLL Library Files. That's why it's able to load PDF file right inside IE Browser.
Note2: Other browsers either use simple built-in PDF Viewers which are not using Adobe Acrobat Reader's DLL library files ... or ... have completely disabled support for NPAPI browser extensions.
Note3: Keep in mind that these IRCC forms have been produced in Adobe LiveCycle Designer ES 10.0 and they require minimum Adobe Acrobat Reader 10.0 to view them. Built-in PDF viewers work on Adobe 9 baseline.
Built-in PDF viewer in Chrome and Firefox don't support Adobe Acrobat 10. You need minimum Adobe Acrobat Reader 10.
That's it!
For Chrome, you need to install and enable 'Adobe Acrobat' extension in order to save files or open them directly from browse to Adobe Acrobat Reader:
Guide : https://helpx.adobe.com/acrobat/kb/open-in-acrobat-reader-from-chrome.html
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(EASIEST FIX IN CHROME!)
That's it! Your files will now open in Acrobat Acrobat Reader!