GALAXY S4 problem! what does this mean and how do I fix it?

[Becky]

The words "Safe mode" are permanently in the bottom left corner of my phone for the past few hours, I've restarted it but had no affect on the problem. Because of this my phone won't let me use a lot of my apps Facebook,WhatsApp, twitter, instagram etc... I want to fix it I pay a lot for an unlimited contract to be able to use these types of apps etc... How will it fix?

[Ultralad]

Take your SIM card out and put it back in, and go into sim settings on your phone, happened on my s3

[solomon]

Safe Mode temporarily disables all applications that have been installed via the Android Market. Performing this troubleshooting step is necessary to determine whether a 3rd party application is the cause of an Operating System / Application issue. Safe Mode should always be performed prior to a hard (factory) reset.

With Safe mode enabled, test device and application functionality. If the previous issue fails to occur, the cause has been isolated to a 3rd party application and all recently installed / updated applications should be uninstalled. With Safe mode disabled, reinstall then test each application, one at a time, to identify which is causing the problem.

To enable Safe Mode

Ensure the device is powered off. To power off, press and hold the Power button

Select Power off

Select OK.
Allow several seconds for the device to power off.

Press and hold the Power button until the Samsung logo appears then release.

With the Samsung logo on-screen, press and hold the Volume down key.

Continue to hold the Volume down key until Safe mode appears in the lower-left of the unlock screen then release.

This may take up to 45 seconds.

To disable Safe Mode

1. Press and hold the Power button
2. Select Restart
3. Select OK

If Safe Mode continues to display on the Home Screen after restarting the device and a Factory Reset does not resolve the problem, it may be due to a faulty Home button which would be considered damaged hardware.