This happens when the characters in some piece of text, which is being called input at this point, cannot be represented in the encoding that something has asked be used. Here the encoding is cp1252, an encoding commonly used on Windows as the default encoding for files and also when writing to your terminal. It’s telling you the first problem is at characters 0 to 3. Not sure why is groups them like that.
I think all we can guess from the information you give is that the AI Thing is writing a string that starts with some characters not in this table.
It is likely it works fine on Linux (which almost always has UTF-8 as the encoding) and the author has not thought carefully enough how it will behave on disadvantaged systems.
If it is writing to a file you opened yourself, the good news is that you are that author! You can choose the encoding yourself when you call open.
… or something else entirely. As Karl writes, there’s really no way of telling from this little information. We’ve all seen this message a hundred times in various circumstances and can’t guess what your are. The full text with stack dump would be a start. (Format it as requested here.)