Unfortunately, the names of the files stored in the NintexFormXML are not particularly user friendly. In the event you need to find an orphaned form in the NintexFormXML hidden repository, how do you determine which form is the form you published? To start, each file in the NintexFormXML hidden library is created using the following format: ContentTypeGUID_listGUID
You can find the content type GUID and the list GUID which may be difficult for some or you can simply review the below methods to find the form file that is being stored in the repository for the list in question.
Navigate to the content type the form is published to in the list using SharePoint designer:
You will see there are links under the "Forms" section for the Content types that are used open your Nintex Form:
The link above contains the following URL:
The highlighted text is the important piece to note here as it reflects the filename for the form that will be loaded when opening a form in the Nintex Forms designer.
If for whatever reason you are unable to find the links on the content type you can also find this using fiddler.
While fiddler is open, open the Nintex Form at the list by clicking ‘new item’ and look for the NFLaunch.aspx request. You can see the structure for the call for in the NFlaunch.aspx request below.
Here is the GET request for that call:
Again we find the same string of text in the content type URL as we do in the above call:
That string is in the format we are looking for inside the NintexFormXML hidden library.
To find this file all that we have to do is navigate to "All files > NintexFormXML" in SharePoint designer:
You u can delete this file, and this is useful in cases where we have a “stuck” form on a list that cannot be edited and we need to delete the design time form so we can load the Nintex Forms designer and republish the form.
You can recover a form XML file by navigating to the Nintex hidden Form library https://yourtenant.sharepoint/sites/yoursite/NintexFormXml/
And find the XML file in the format ContentTypeGUID_listGUID that matches the List GUID and downloading a copy of that file and rename the extension to .xml and then import it in Nintex Forms designer.