In order to fix the issue, open your Android device, navigate to Settings > All Settings > Apps/Applications, tap the EagleViewer Pro icon and clear all data and cache. After that, try again to open the files. If it doesn't work, remove the software and download and install it again from Google Play Store. If you still can't open the files, open File Explorer, navigate to your Eagle files directory and check the files format. EagleViewer Pro can open only .brd and .sch files. For further information, use
email@example.com email address to get in touch with the developer.