One of the end users that I support reported an issue with her install of Acrobat Pro DC2015. When she tries to import a document (word doc or pdf) to create a form, the Start button is missing.
My first step was to uninstall the program and then install it fresh, and then install latest updates. At first the program behaved normally, but after an hour or so the end user reported that the issue had returned.
Computer is running Windows 7 Enterprise (32-bit), user account is a standard user (no administrative rights on the box).
Sorry for the delay in response to your query and apologize for the inconvenience caused. As per the description above, the Acrobat Pro DC is unable to import a Document to create a form, Is that correct?
If the issue persists, please try to reset the preferences of Acrobat Pro Dc, to reset the preferences, refer to How to reset Acrobat Preference settings to default. Link: https://forums.adobe.com/docs/DOC-8511
If this does not fix the issue, please use the Acrobat cleaner tool to remove the Acrobat, Cleaner tool Download Adobe Reader and Acrobat Cleaner Tool - Adobe Labs Link: http://labs.adobe.com/downloads/acrobatcleaner.html
Restart the computer and then install the Acrobat back from Download Pro or Standard versions of Acrobat DC, 2017, XI, or X Link: https://helpx.adobe.com/acrobat/kb/acrobat-downloads.html
Hope this helps and keep us posted with the results.