Wrong information in my thesis
If you aren't allowed to make a correction then you can't and it is what it is. But since it was accepted, there should be no issue for the thesis or for your degree. 

However, in the future, if you do a publication that needs to cite the thesis, you can make a correction there. I assume, of course, that the error doesn't call your main result in to question. In that case you would need to either ignore the past or give a rather extensive update to your thesis in a new paper. 

People make mistakes. People correct mistakes. Science moves on and advances. 

Your thesis probably won't be the last piece of work that you do.