We have a Biacore 3000 that occasionally throws an error. Since they are all numbered, it was always unclear what the errors were. Mystery solved. I was able to find error list by going into c: > Program Files > Biacore > Service (might be a hidden file on your machine) > Big list of files.
A few of them have 'err' file name and can be read as text files and list most of the error codes I have seen. I would recommend making a copy of them on a safe location before renaming them .txt.