Problems with installation from unknown source.

[Android Central Question]

Everything goes fine until it's almost done bu then it displays this screen. App not installed. With a ! inside a triangle.

 

[B. Diddy]

Welcome to Android Central! Which device? What app are you trying to install, and where are you getting it from? Since it's clearly not from the Play Store, there's no guarantee it's compatible with your device (and there's always the risk of malware, so think twice).

Please register on this forum, which will allow you to engage in discussion more easily, as well as post images. https://forums.androidcentral.com/ask-question/409154-join-android-central-community.html

 

[smvim]

Please give more details, otherwise your query is just too vague and meaningless to make any appropriate suggestions.
-- What is the name of the apk file?
-- Where did you downloaded it from?
-- What device do you have and which version of Android its running?