Hello @allformailers,
Such issues occur most commonly when a JavaScript file is not written in accordance with the strict coding standards. In these cases, the Combine JavaScript Files function is not able to properly combine the file, since it uses strict coding logic to complete the combination process.
You can use the Exclude option on the function’s page to exclude the problematic script from the combination process. If you do not find the script there, you can follow the guidelines here to add an exclusion filter.
If you need further assistance, I see that you are a SiteGround customer. In this case, your best option is to post a Support Ticket through your User Area, instead of a post in the forum here. This will allow our team access to your site, so that we can test a solution for you.
Regards,
Plamen.M
Tech Support Team
SiteGround.com