The most common culprit is a slow or unstable connection. Run a speed test — streaming in HD requires at least 5 Mbps, and 4K content needs 25 Mbps or more. If the numbers look fine, try switching video quality manually in the player settings instead of leaving it on Auto. Clearing the app cache also helps: on Android go to Settings → Apps → Crunchyroll → Clear Cache, on iOS just reinstall the app.
Force-close the app and reopen it. If that doesn't help, check whether your device OS and the app itself are up to date — outdated versions cause a lot of random freezes. On smart TVs and consoles, a full power cycle (unplug for 30 seconds) often does the trick better than a simple restart.
If you're getting an 'incorrect password' error and you're sure the credentials are right, try resetting the password via email. Sometimes the session just gets stuck — logging out of all devices through account settings clears it. Also check that your email address in the account profile is entered correctly and confirmed.
If an episode appears in the list but won't play or shows an error code, the content might be temporarily unavailable in your region, or the file itself has a delivery issue on the platform's end. Try searching for the same episode directly instead of going through the series page — sometimes the deep link works when the series page doesn't. For missing subtitles, switching to a different subtitle track and switching back usually reloads them correctly.