[Koha] record won't delete

[Lauren Denny]

Hi everyone,

I have a record that will not delete. When I try to delete the record or
merge it with another record I get this message:
An error has occurred!*Error 500*This message may have been caused by any
of the following reasons:

   - You made use of an external link to an item that is no longer available
   - You followed an outdated link e.g. from a search engine or a bookmark
   - You tried to access a page that needs authentication
   - An internal link in the client is broken and the page does not exist

What's next?

   - Use top menu bar to navigate to another part of Koha.
   - To report a broken link or any other issue, please contact the Koha
   administrator. Send email <library%40teamwork-global.net>

Does anyone have an idea of what is happening?

Lauren