Fix unfortunately IMS service has stopped

IMS means Internet Messaging Services. You need to Open the SMS app and go to configuration messages. Look for old configuration messages rather than installed one and install it. The IP Multimedia Subsystem or IP Multimedia Core Network Subsystem (IMS) is an architectural framework for delivering IP multimedia services. Historically, mobile phones have provided voice call services over a circuit-switched-style network, rather than strictly over an IP packet-switched network.