Holiday List link in email gives error

Hi all, a new bug on my end. I have just configured a holiday list for our Indian office.

The PDF creation and email works perfect. The bug I have is when clicking the URL in the email that says: “View this on our website” it loads ERPNext with:

SERVER ERROR and gives the following error message: erpnext calendar issue -

I have ERPNext running on 2 servers, one on Lindode for production and one on Digital Ocean for testing. Both are Debian 7 boxes, one with SSL, one without. Both throw the same error when clicking the message.

Can provide screenshots or any other info if needed.