Download of PDF link in older Android legacy brwoser and Chrome

[thlinna]

I've been investigating a problem that exists with people running not-the-latest Android tablets or phones. I am running PW 3.0.32, ProCache and Let's Encrypt SSL. Regardless of having nginx or apache web server the same problem exists. User clicks on a pdf link from my site, all they will get is blank screen. Nothing happens. No entries are found in either access or error logs or PW logs. 

This problem exists with Android stock browser and Chrome on Android version 4.4.2, but not with (latest version of) Opera on the same device. Maybe needless to say, but I cannot reproduce the error with iOS or OSX versions of the common browsers.

Maybe this is has nothing to do with PW, but I was not able to find any applicable sources for investigating the issue.

So any help or pointers would be appreciated. Thank you in advance :).

[horst]

Only thing I can imagine is that you will need sending special HTTP headers for those browser / os combination. So, I don't know which one(s). That you need to investigate by googling, maybe?

If this is a way that turns out as a practicable workaround, we can show how to implement sending additional headers from within PW (templates).

Sorry, that I'm not able to tell you more.

 

[thlinna]

@horst, thank you for your answer! That may be the one we need to do, must investigate it further.

We were able to narrow this issue a little bit. It seems that Apache mod_security2 with OWASP rules gave a few false positives. After disabling those rules one need to clear cache of android application, that can be done via settings -> application settings. That solved some of the cases.

However it did not fix the problem with Android 4.2.2 legacy browser. It does not get updated any more. A workaround is to install newer Google Chrome or equivalent which get updated from app store.