What does a circle with line thru it icon mean

[AC Question]

I have a Samsung phone and I went to send a text this icon came upon the top of the screen.,now my text messaging is not sending

 

[Sam_Gs7]

Not sure but I read out in an ACentral thread-That means
you've by mistake Turned on the -Do Not Disturbs- setting
So that review if his feature is enabled try to disable it