On opening a page based on a template(*.dwt) in DW CC 2019 I get an error. The error did not occur until I added BootStrap 3 Components to the site master template page.

I get the error:

While executing onLoad, the following JavaScript error occurred: At line 922 of the file "C:\Program Files\Adobe\Adobe Dreamweaver CC 2019\Configuration\Commands\dmxUpdateHead2.htm": The object is not currently contained in a document.

This happens only on first load of the page into DW. If I detach the template from the page, save the file, and then re-open the file. Error does not occur.

I cleared the DW cache file thinking it corrupt. No happiness. Didn't help.

Not seeing any Javascripts out of place (not in the header). So something in the template is suspect? Any suggestions?