To resolve the issue of the Newsmax app crashing on your Amazon Fire Cube, follow these detailed steps:

1. Clear App Cache and Data:
- On your Fire Cube, go to Settings.
- Choose Applications.
- Select Manage Installed Applications.
- Find and select Newsmax.
- Click on Clear Cache and then Clear Data. This helps reset the app's status and can eliminate crashing issues.

2. Uninstall and Reinstall the App:
- Still under Manage Installed Applications, find Newsmax.
- Select it and choose Uninstall.
- After the uninstallation is complete, go to the Amazon Appstore and reinstall the Newsmax app. This can fix bugs associated with the app installation itself - learn more.

3. Restart Your Fire Cube:
- You can restart the device by going to Settings and selecting My Fire TV, then choosing Restart. Alternatively, unplug the power adapter for about 1 minute, then plug it back in. A restart can refresh system resources and resolve temporary issues - learn more.

4. Ensure System Software is Up-to-Date:
- Go to Settings.
- Select My Fire TV and then About.
- Choose Check for Updates. If there’s an update available, install it. Keeping your device up-to-date can help with software compatibility, particularly with apps like Newsmax - learn more.

5. Free Up Device Storage:
- Sometimes a lack of storage can cause apps to crash. Go to Settings > My Fire TV > About to check available storage. Remove any unused apps or content if space is limited.

6. Factory Reset (Last Resort):
- If the app continues to crash after trying the above steps, you may perform a factory reset. This will erase all data on the device.
- Go to Settings > My Fire TV > Reset to Factory Defaults. Follow the prompts to confirm. After resetting, reinstall the Newsmax app.

7. Check for Alternative Issues:
- If none of the above steps resolve the issue, check your internet connection, as slow or unstable internet can also result in app crashes. Try restarting your router.

If you experience persistent problems even after these steps, it may be beneficial to reach out to Newsmax's customer support for assistance - learn more.