In some rare situations BBM get this type of error. This happens between BB users. My friend contacts some one few days ago. The conversation goes well on both side. But immediately the chat is cut and my friend got big red X on his phone. This is frustration when the communication intrupt if we chat between others. The red X continues almost 10 minutes; there is no luck to contact again with that particular friend. Here I want to mention one thing; my friend able to receive messages, but can’t Send him. If he try to respond his friend messages, on that time a check mark will display. So he can’t send any messages. After that he try lot of methods through local service guys, there is no luck. Basically this situation happens lot of Blackberry users. The real reason behind this issue I will give up on the below. 

Basically BBm service is really secure and uninterrupted anything. so no doubt there is no mistake in Blackberry side. The fact of service interruption was happened through Sim Card. Yea, lot of mobile networks upgrading their service to next levels. For example on the time of Smartphone releases we are using the same internet connection like our voice calls. Now a days the SIM internet cards especially for Smartphone’s reached 4G. So some old type sim cards not working lot of phones. So if we replace our old sim card to new micro-sim the problem will solve easily. Other than this solution nothing works like upgrade operating system, changing hardware products etc. If you are interesting to send picture messages check out this site you can find 100's of amazing information about Dp's and BBm.