Hueber has made minor updates, but the core exercises rarely change. Check the copyright page. If your ISBN ends in -902-8 (for the Kursbuch), solutions from the corresponding Lehrerhandbuch (ISBN ending in -902-8 as well) are safe.
Since the Kursbuch is designed for classroom use with a teacher to correct answers, self-learners often struggle. Here are tips to check your work without a teacher: menschen a2 1 kursbuch loesungen