The app will verify its integrity and download additional configuration files. Once a green checkmark appears, you are ready to log in.

: Is this related to a specific piece of hardware (like a 3G modem or a laptop model)?

Insufficient storage or conflicting security software. Fix: Free up at least 300MB of space (even if the app is 150MB, it needs room for decompression). Temporarily disable Play Protect (Google Settings > Play Protect > Scan apps).