What kind of forms are you downloading? If they are PDFs (served as application/pdf content type and having a .pdf extension) I would expect the same behavior as for non-fillable PDFs. If they are something else...

NO document will open Are you Mozilla? I'm not looking for a bloggers guess How do I adjust setting for downloads?

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Describe where the process stops working in Firefox and whether you get any error messages:

• menu > Tools > Downloads
• tap a file to open it > Android may prompt for which application to use
• download launches in the designated application

They are forms(know what the word means) Most PDF but not all No error, no offers of applications, nothing after clicking link in downloads

Tap file...then nothing Absolutely nothing else happens