There are many problems that may occur while you are meditating, here are few of the problems which may occur:
1st is the desire not to meditate while you are meditating
2nd is the feeling of antsiness while you are meditating.
3rd Not able to focus on your breath but still being in a state of consumed with thoughts
4th feeling like you are not meditating when you are meditating
There are many more challenges that may appear when you are meditating, the point is that it is okay to have problems with meditation while you are meditating the biggest thing is to just to work with meditation and keep with it.