Poor language skills can lead to a (an)

If you are referring to this question:
What kind of block can result from poor language skills?
Poor language skills can lead to a (an)

The answer would be a mental block. This is a common occurrence when learning things, but it is notable in language learning. At times, they also call this a plateau of the mind. Poor language skills can impede the train of thought, which can also cause this type of block.