Rediection import error

I am getting an error when trying to import a csv into Redirection.

The error is in this form:

Fatal error: Cannot instantiate abstract class Red_FileIO in /home4/example/public_html/example.com/wp/wp-content/plugins/redirection/redirection.php on line 294

This is happening even when I export to csv from the plugin and then try to immediately upload it, without modifying it first.

Any ideas what the problem might be?

https://wordpress.org/plugins/redirection/