Verizon Samsung Galaxy S4 SCH-I545 Android 4.2.2 Baseband version I545VRUAME7 Never rooted I have had a Samsung Galaxy S4, through Verizon, since it first came out. The device was never rooted. It worked fine until a few weeks ago, when it developed a strange cluster of intermittent problems: 1. The contacts, which are synced from a personal Gmail account and a work Exchange account, just vanish on the phone. When the problem occurs, if I run the Contacts app, it displays no contacts at all. If I choose the "Contacts to display" option from the menu, sometimes it displays a blank screen, sometimes it displays "Initializing SIM card," and sometimes it displays "Updating contacts." All the contacts are still intact on the respective servers, as well as on my Nexus 7 tablet. The email and calendar items from these two accounts work normally. Only contacts are affected. Just as suddenly as they disappear, they will spontaneously reappear on the phone. 2. Text messages usually cannot be sent or received when the problem is occurring. I can sometimes send a text by entering the phone number manually, but names cannot be used, since the contacts are not available. 3. I often cannot dial outgoing calls. I can receive incoming calls, but cannot dial out. This seems to be because the Phone app is trying to access the contacts, which are not available. 4. The problem usually is not resolved by power cycling the phone, but often when I try to power cycle it, it hangs on the Verizon splash screen during boot, forcing a battery pull. This often happens 3 or 4 times in a row. I spent hours on the phone with Samsung tech support. They thought it might be a SIM card issue. They suggested a new SIM card. Verizon gave me a new one. It was fine til the next morning, when the problem recurred. The next suggestion was that the SIM card reader may be bad. Verizon provided a replacement phone, which worked fine for a few days, then started doing the same thing. The original phone, with no SIM or SD cards installed, also continued to have the problem. The next suggestion was another factory reset after disabling the automatic app and setting re-installation. I only reinstalled the apps I use most frequently. Again, it was fine for a couple days, then started again. I have tried uninstalling various apps, but inevitably the problem comes back. At the time the problem began, I had not made any recent configuration or app changes, so nothing jumps out at me as a potential cause. Except for the problems listed above, all the other apps and functions are fine. However, when this occurs, it really cripples the phone. Has anyone heard of a problem like this before or have any suggestions? I did not find any similar threads in the forum. Thank you for your assistance.