Back as DaveOC. I tried a few things on my sandbox computers, one is a totally generic Windows XP, Firefox 47.0, IE 8.0.
I logged in to solsticeforum as DaveOC, tried to leave a reply and had it generate the error in both Firefox and IE.
I logged into SF from my wife's account, which is never used, replied to this message, and shortly thereafter had a reply page in front of me, no error. I logged out.
I logged in with a generic login I use here when I don't wish to appear online as DaveOC, tried to leave a Reply, and had no error.
Logged back in as DaveOC, tried to leave a reply or a quote and both generated the script error.
I repeated this same sequence on another sandbox computer, Win7, Firefox 47.0 and IE 11, with the same logins and results.
Acid Test: I returned to this computer where I spend most of my time during the day, logged in as DaveOC, went to leave you a message and generated the script error. Logged in as my wife, no errors when trying to reply to this thread, and had same results, no errors when trying to reply as my generic login.
Logged back in as DaveOC and am now leaving you this message.
With all three logins I used on all three machines, I did not generate the error when using the "Quick Reply"
What's the difference between you as Administrator, my wife's login, and my generic login to this forum, versus my login as DaveOC?
Answer: A long list of attachments associated with my DaveOC login.
Rob the Elder, who is experiencing the same issue also has that long, long list of attachments associated with his login.
My testing today have pretty much eliminated everything you mentioned in your first post.
Hope this helps.
FWIW, please leave a reply to this after you have read it, so I know you are working on it.
1st 1K - #741