The app scans several different online data sources attempting to get as much information as possible about the item you have entered. Since I am not allowed to have API access to most data sources, I have to scan the public website information for the data I need.
This has several drawbacks because the websites are not uniform and structured for every item. This forces me to code in all sorts of checks and cases to handle many many different options. Occasionally I miss something and you will find one or several items that cause the app to fail.
In this instance, simply send me the item code (ISBN, UPC, EAN) for the item and I will figure out what the issue is and fix it for the next release. I release updates on a regular basis, sometimes as quickly as a few weeks apart, so issues won't persist long.