None at the moment. If you encounter an issue, contact the maintainer(s) with a detailed description of the issue and with a description of the setup you were using.
The current version of the aaltoseries class has an issue with the hyperref and natbib packages. If the document at hand uses *both* of these, compilation results in an error. However, if either one is not used, the document will compile smoothly without any problems. This seems to be an issue with the titlesec package that the aaltoseries class uses to set the formatting of section headers (part, chapter, section, etc.). Hopefully this issue will be resolved in the next version of the class. RESOLVED IN VERSION 1.1!