Hello and welcome to just answer Chrysler. This tells me that the communication bus network has a problem. There are 3 different communication networks in your 300C the CAN C bus, the CAN B, CAN C diagnostic, and the LIN bus. There are many modules (computers) in your car (up to 20 in some cases). They all communicate to each other on the bus circuits. There is a front control module under the hood that acts as a gateway for the network. Now when a bus circuit fails it can cause minor issues such as a cluster not working, a sunroof that won't open etc. But a massive failure can cause the engine to die and maybe not start. Bus failures can be caused by a wiring problem or one of the modules on the bus could take the circuit down. The only real way to diagnose this is by using the Star Scan scan tool which at this time is a dealer tool only. I recommend taking your 300C to the dealer and have them troubleshoot why the bus is down. It may be an item covered under warranty, (like a failed PCM).
Hope this information is helpful. Let me know if you need more assistance with this.