email services extension

I got the following error when installing the extesion richmail from email services pack:

Upload and Publish Extension RichMail

Uploading Uploaded Extension to HubServer.
Upgrading Upgrading Extension. A new version will be created.
Verifying Verifying Extension definition.
Invalid Text Value 'Description' value cannot have more than 255 characters.
Error(s) found 1 error(s) were found in this Extension's definition.

Can anyone correct this?

Thanks in advance

Pedro A. da Ponte