LG K4 2017 - Problem Installing APK

[shinnen]

Hi,
I have an LG k4 2017 phone, which tells me that it "can't open file" when I try to install an apk for a pdf reader. I have set the security to allow unknown source, but it didn't help. It will open other files (media) and I have installed other apks in the past, i.e. the Opera browser. It is connected to the internet, but I do not have it on a phone plan. This phone is Android 6.
Any help is appreciated.
Thanks,
...... john

 

[Traveller]

Which app? You may have to install an older version of the app as newer versions may no longer support that version of Android.

 

[shinnen]

Hi Traveller,
I hope you're well.
I tried 2 apps
com. gsnathan.pdfviewer_28.apk
and
PDF Reader-tencent_5.1.6.apk
.... john

 

[Traveller]

Ok, now that I have had a chance to look a little more deeply, have you uninstalled the previous version before installing this one? For example, if you installed a version of com.gsnathan.pdfviewer from the Play Store you will not be able to install the F-Droid version until you uninstall the Play Store version. This is due to the two versions having different signatures.

As for the Tencent PDF viewer I can't really help you. You may have the same issue there as above, but Tencent may have changed the signature. I personally stick to Adobe software to get the job done so as a result I don't have these kinds of issues and consequently I am not readily familiar with alternative readers.

 

[shinnen]

Hi Traveller,
When I tried to install the two mentioned apps, I got the message 'can't open file'. Maybe there was one put on it before (it's my wife's old phone); but it wouldn't open the pdf's, so I assumed that one has not been installed.
Thanks.
..... john

 

[Traveller]

Hmm...unless you are having an issue with RAM, which is possible, you might want to look into performing a factory reset on the phone.

 

[shinnen]

Hi,
I'm reluctant to do so, but will if necessary. Tell me, do these phones normally have a pdf reader in the native OS? Is there a way of resetting the settings to default, without going to the factory reset?
Thanks,
..... john

 

[Traveller]

Whether a PDF viewer is included or not depends upon the phone. For example, Google phones don't include one, though I'm fairly sure Chrome can be used for the purpose just like on a PC. As for a settings reset, that cannot be done without doing a factory reset. I would make sure to back up everything on the device before going that route.

 

[shinnen]

OK Traveller.
Thanks very much for your help.
.... john