I'm using Xioami's MI 9 SE phone.

I have several PDF viewer apps installed: Mi Doc Viewer, Pdf Viewer Plus, MuPDF viewer...

However - whenever I try to open a PDF with one of these, or even with a file manipulation app, from a browser - I either get some error message (e.g. lack of permissions which I can't change, or some blurb in Chinese) - or just an empty screen.

Here are two screenshots, of the errors with two apps  , when I try to open a file via my (Opera) browser Downloads screen. The file I try to open is desktop.pdf; when pressing it, I'm presented with an app selection dialog, and whichever app I choose, it doesn't work.

With "MI Doc Viewer (Powered by WPS)":

With "Document Viewer":

What might cause this problem, and how can I circumvent or fix it?

PS - I don't get this for other file types (at least, not that I've noticed).

I'm using Xioami's MI 9 SE phone.

I have several PDF viewer apps installed: Mi Doc Viewer, Pdf Viewer Plus, MuPDF viewer...

However - whenever I try to open a PDF with one of these, or even with a file manipulation app, from a browser - I either get some error message (e.g. lack of permissions which I can't change, or some blurb in Chinese) - or just an empty screen.

Here are two screenshots, of the errors with two apps, when I try to open a file via my (Opera) browser Downloads screen. The file I try to open is desktop.pdf; when pressing it, I'm presented with an app selection dialog, and whichever app I choose, it doesn't work.

With "MI Doc Viewer (Powered by WPS)":

With "Document Viewer":

What might cause this problem, and how can I circumvent or fix it?

PS - I don't get this for other file types (at least, not that I've noticed).

I'm using Xioami's MI 9 SE phone.

I have several PDF viewer apps installed: Mi Doc Viewer, Pdf Viewer Plus, MuPDF viewer...

However - whenever I try to open a PDF with one of these, or even with a file manipulation app, from a browser - I either get some error message (e.g. lack of permissions which I can't change, or some blurb in Chinese) - or just an empty screen.

Here are two screenshots, of the errors with two apps , when I try to open a file via my (Opera) browser Downloads screen.

With "MI Doc Viewer (Powered by WPS)":

With "Document Viewer":

What might cause this problem, and how can I circumvent or fix it?

I'm using Xioami's MI 9 SE phone.

I have several PDF viewer apps installed: Mi Doc Viewer, Pdf Viewer Plus, MuPDF viewer...

However - whenever I try to open a PDF with one of these, or even with a file manipulation app, from a browser - I either get some error message (e.g. lack of permissions which I can't change, or some blurb in Chinese) - or just an empty screen.

Here are two screenshots, of the errors with two apps , when I try to open a file via my (Opera) browser Downloads screen. The file I try to open is desktop.pdf; when pressing it, I'm presented with an app selection dialog, and whichever app I choose, it doesn't work.

With "MI Doc Viewer (Powered by WPS)":

With "Document Viewer":

What might cause this problem, and how can I circumvent or fix it?

PS - I don't get this for other file types (at least, not that I've noticed).

I'm using Xioami's MI 9 SE phone.

I have several PDF viewer apps installed: Mi Doc Viewer, Pdf Viewer Plus, MuPDF viewer...

However - whenever I try to open a PDF with one of these, or even with a file manipulation app, from a browser - I either get some error message (e.g. lack of permissions which I can't change, or some blurb in Chinese) - or just an empty screen.

What might cause this problem, and how can I circumvent or fix it>?

I'm using Xioami's MI 9 SE phone.

I have several PDF viewer apps installed: Mi Doc Viewer, Pdf Viewer Plus, MuPDF viewer...

However - whenever I try to open a PDF with one of these, or even with a file manipulation app, from a browser - I either get some error message (e.g. lack of permissions which I can't change, or some blurb in Chinese) - or just an empty screen.

Here are two screenshots, of the errors with two apps , when I try to open a file via my (Opera) browser Downloads screen.

With "MI Doc Viewer (Powered by WPS)":

With "Document Viewer":

What might cause this problem, and how can I circumvent or fix it?