In my experience this has been a problem caused by a faulty keyboard. If you have another keyboard available try that and see if the issue goes away.
Not without keyboard problems.
Is InDesign the only program where you're having problems with the lowercase "c"? Does it work fine with the Shift key? How about other Adobe applications? How about a generic word processing app like Windows WordPad or MacOS TextEdit?
If for some reason, after checking all of that, InDesign is the single app with this problem, all I can suggest is resetting your preferences. It's the first stop for correcting truly odd and/or infrequent problems with InDesign. You can find out how about a third of the way down of the page connected to the link below:
Hope this helps,
I had created a character shortcut under 'c'! I reset my prefernces and it works perfect
thank you for the reply
It's generally a good thing that Adobe apps let you map custom keyboard shortcuts (and MacOS, and Windows, for that matter) to automate repeated tasks. But there's always a danger when you're peeking deep under the hood that the Law of Unintended Consequences can reach up to bite you.
I'm glad that things worked out well for you. Can I ask a favor, though? If you'll mark your question as answered, it'll alert the moderators to flag it for users who have similar problems. That way, when they run across the issue it'll show up for the next user in the "Related conversations" list you see at the bottom of this thread.
And if you have any other problems in the future, please don't hesitate to come back here and call for help. There are lots of sharp people around here who are happy to lend a hand.
Hope the day treats you well,