What is errors and omissions insurance?
Errors and omissions insurance, commonly referred to as E&O, covers you in case of lawsuits regarding any error, omission, defamation, invasion of privacy, emotional distress, copyright/trademark infringement, or misappropriation resulting from your work.
This type of coverage is often contractually required by film distributors. If you are looking into distribution of a film, errors and omissions insurance may be a good option for your needs.
Example of an E&O Claim:
A famous recording artist sues you claiming that you've violated their copyright by including their song in your movie.