I'm not trying to be obtuse and I understand the importance of full conflict testing but I am trying to exhaust my options before I go through and start disabling plugins. Every plugin I have activated plays a role in the site and I disable / remove any plugin I am not using.
It seems weird to me that there is no error on the page. I redownloaded and reuploaded all the files for wpForo to make sure it wasn't a corrupt file. I also skimmed through the frontend.js file that wpForo was loading to see if there were any jQuery scripts that might be called twice and didn't see any. I am loading some jQuery scripts outside of WordPress plugins but didn't see anything in your code that looked familiar.
One thing I did notice in the console was that when I had Advanced Attachments enabled it loaded it's javascript files over and over and over again. I included an image showing the weirdness.
I disabled that plugin, it's not necessary to my forum but it would be really nice. And I did buy it just for this site.
I really appreciate any and all help with this, I understand this is a free plugin and you are giving me support. I did buy two addons for it and will be recommending this to people in the future. I would even be willing to make a donation to your company or buy the rest of the addons if we can get this working.
I can do conflict testing tomorrow (it is 4am here)- but it just strikes me as weird that there are no errors.
EDIT: I see now that the advance attachment script names were just wrapping and I am tired so I didn't notice them. Woops, I guess that wasn't messing anything up.