iMessage not working on Mac

I am running a printing business for a couple of years and It was running smooth.For a days or two I am facing severe consequences regarding that I am unable to take printouts and take a screenshot from my macbook regarding the 3d designs which I have made.I have tried out the manual configurations as instructed by the support team to figure out this consequences regarding the iMessage not working on Mac
Suggest what to include to resolve this issue permanently.