I agree with the others - dispute this as "not mine".
Based on some of my research, I believe (don't quote me, though) that this entry appears if this was from a creditor (usually a collection agency) that is no longer in business. If the date last reported is really old, it may be a entry from a collection agency that's no longer in business.
It's not your fault if the CRA's program to generate the credit report has a bug
- dispute it. You don't know what it is, and they shouldn't report it if they don't know what it is, either.