AbleCommerce Shopping Cart Software

I am getting an error that our store is having trouble generating email messages for all sorts of our templates.

Error generating email messages for template 'ESD file is activated' having subject 'Your digital good is available for download'.

Plus, I have several other errors for other email templates. Any suggestions on how to fix them?

Most probably you have attempted to edit the Email templates with FCK editor's design mode. Its a known issue that if you use FCK editor design mode and then save changes it corrupts nvelocity scripts. You can try restoring default Email templates available.