InfoPath Dev

I have a SP2013 Site that has an Infopath Form Library on it. I need to make a change to this form that I have inherited. I have turned off Content Types so I am able to click on "Edit Template", but when I do it says "Sorry, we couldn't open "http://sharepointsitename/operation/AuditTracklng/Forms/template.xsn." We have all of our services turned on. I inherited this form and doc library and was told by mgmt that the domain had changed from when we acquired this other company. So, the form itself still works on the site but I can't find a way to EDIT the template. I have searched and can't find any answers. Any help would be appreciated.

Can you open the library in Windows Explorer? If you can, the template file may be in the folders - if I recall correctly, it is in the Forms folder (which the URL indicates). You mention you turned off content types - but was the template a content type? If so, it may be someplace else.... If you download one of the completed forms and open the XML file in a text editor, there should be an "href" attribute toward the top of the XML that will tell you for sure where the template is. Oh, another thing you might try - open InfoPath Designer and then go to File > Open and put in that URL from the "Sorry can't open" message, if you are pretty certain the form was published directly to the library and isn't a content type.