q: How to use the basic app?

a: Please watch the following video: https://www.youtube.com/watch?v=bIa3YC_BvR0

q: My app doesn’t load the pdf?

a: Try closing all apps and opening the app again from the email or messenger,  usually the bugs on the first time to use the app.

q: Now all pdf files opens on CBCT-Ruler, how do i change it back?

a:    Go to Settings -> Apps -> All.
Scroll down to Google PDF Viewer app and tap on it.
Scroll down to the Launch by default section and tap the “Clear Defaults” button.

q: I get error massage while using the app

a: Try closing the app, clearing the cash, quit other apps, and try to open it again. In some instances one should reboot his device.

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