Problem with template attachments in mail notifications via custom action.

Problem with template attachments in mail notifications via custom action.

Hi, Im experiencing issues with pdf attachments on our emails since yesterday.
For some reason the record summary pdf seems to loss its format or render incorrectly.

I had implemented email notifications via a custom button in my report as in the following:
https://zoholic.blogspot.com/2016/01/zoho-email-notification-with-record.html
which has worked like a charm for more than 2 years, until 2 days ago.

I attach some pics to clarify the problem:

Incorrect PDF...the templates are sent rendered wrong.

Correct PDF...How the templates were sent couple of days ago

Hope i can get some help on this issue.

Thanks
Iván