Sorry to necro-post but for those who are seeing this article, yes it can be a file name issue.
Acrobat products have historically opened a PDF as long as the %PDF-header started anywhere within the first 1024 bytes of the file. No checks were performed on the extraneous bytes before the %PDF-header. However, the 10.1.5 and 11.0.01 updates improve security by enforcing stricter parsing of the PDF-header. The product now refuses to open the small fraction of PDFs that do not correctly start with the '%PDF-' header.
You can disable the header validation on machines by setting the appropriate preference
If the AVGeneral key does not exist, create it manually.
The HKLM path is generically:
HKLM\Software\Adobe(product name)(version)\AVGeneral\bValidateBytesBeforeHeader=dword:00000000
For example, to change the behavior for Acrobat 11.0, create a DWORD at this location: HKLM\SOFTWARE\Adobe\Adobe Acrobat\11.0\AVGeneral\bValidateBytesBeforeHeader=dword:00000000
The HKCU path is generically:
HKCU\Software\Adobe(product name)(version)\AVGeneral\bValidateBytesBeforeHeader=dword:00000000
For example, to change the behavior for Reader 10.0, create a DWORD at this location: HKCU\SOFTWARE\Adobe\Acrobat Reader\10.0\AVGeneral\bValidateBytesBeforeHeader=dword:00000000
Always change the product and version number in the preference path to match your installation. This method allows the PDF to display on machines you control.
https://helpx.adobe.com/acrobat/kb/pdf-error-1015-11001-update.html