Hi,
I have a LG G4 phone with Android 6.0 and I was successful install Call Recorder - ACR v15.3.
I downloaded another version of Call Recorder - ACR and tried to update. but it shows the error "Application not installed".
From Google Play, the update works perfectly.
This error appeares when I want update installed application.
How resolve this problem without remove application? I want keep the dates din app.
Thanks

How resolve this problem without remove application? I want keep the dates din app.

At a guess, wait for the update to appear on Google Play. Apps are digitally signed by the source you get them from. If you get the app from one source, and try to get another version from a different source, the signatures won't match, and you won't be able to install the new version without first removing the old one.

I went through that because I have apps from the Play Store, and apps from the F-Droid Android open source repository. Many apps are on both places, and I have to pick one per app and stick to it.