ahh it looks like removing the image gets rid of the error, but it isn't referencing the SB account... but thank you, at least it is stopping the error!

We ran into this exact issue yesterday. The issue (for us) was that the URLs are actually wrong. Not sure why/when they changed it, our templates hadn’t been changed since… 2016? Try converting them to account specific urls: Was:

<https://system.na3.netsuite.com/core/media/media.nl?id=5302035&c=xxxxxx&h=etindco30js2sqw313ok>

Now:

<https://xxxxxx.app.netsuite.com/core/media/media.nl?id=5302035&amp;c=xxxxxx&amp;h=etindco30js2sqw313ok>

Worked for us!