DevDevmon Subscriptions CRON URL Triggering Error Page

Question

Subscriptions has been working fine for several weeks, but all of a sudden, a bunch of my subscriptions slipped into "Past Due" status. I tried to manually enter the module action URL in my browser (they have it programmed to display a status of what happens as it attempts to renew any past due subscriptions), but after outputting a few rows it reloads, this time using the EE Error template (user message template), and refuses to continue.

The "error" was something about a missing {/if} or errant } or something. This didn't make any sense because the action url shouldn't invoke the template parsing engine.

How could something in the Subscriptions update process trigger an error in the template parsing engine?

Answer 1

Believe it or not, this was caused by an error in one of my email templates.

When a subscription attempts to renew, it fires a trigger based on what the result of that renewal is.

If you have a "send email" action linked to that trigger, the template parsing engine will attempt to parse the email template in order to fulfill action.

If the email template has an error in it (as mine did), this will cause an unholy crossing of the Subscription CRON url page and the EE error template.