Traveling to Europe with a criminal record?

A family member is due to visit me in Europe this summer. They applied for and received a passport, but they have a extensive criminal record(no new charges in the last 3+ years and are not on probation). They will be flying to Germany and visiting various EU countries. My concern is that they could be denied entry. I have searched around on the net for reference and it seems like it should not be a problem but just wanted to confirm here that indeed it should not be a issue. Any information provided is much appreciated.

I have traveled twice to Austria for business during the last two years, and I have ongoing projects there that require me to visit at least three more times.

My problem lies in the fact that I have recently been found guilty of two criminal charges. Resisting arrest and Obstructing an officer in the course of his duty.

Therefore my question is: will these charges prevent me from entering into the European union?

They could yes; you may want to arrange a visa in advance if you don't want to risk being stopped at the border.