The paid app and subscriptions are 2 different versions designed for different user groups. If you purchased the CamScanner license via Google Play, the app will be listed as "purchased" on Google Play and you can install it again freely. If it still doesn't work, pls report to us from the CS app--Me--Feedback. Thanks
Sorry that we have to monetize via advertising now to support our R&D. You can click the "x" or "skip" on the ads to close it in the app, or upgrade to premium to remove all ads. We will also improve our app.
If you can't close it or view the ads frequently, pls send us the screenshots and report from CS app->Me->Feedback for analysis. Thanks