I ran in to the protected mode issue in native Acrobat Reader X while launching attachments from a virtual app. I decided to add a couple of lines to Package.ini :
ChildProcessEnvironmentExceptions=acrobat.exe;acrord32.exe
ChildProcessEnvironmentDefault=Virtual
In addition to these lines, if your application's file system isolation modes are Full and WriteCopy, then you may need to make one more tweak. Our application was outputting files to its own temporary directory in the sandbox instead of using the Windows TEMP or TMP settings. We had to find that folder and set it to merged. We can now open PDF attachments from our ThinApp application and Acrobat X is able to see the files when the application extracts them to its temporary directory. We did not need to disable Acrobat Reader X protected mode within the ThinApp registry.
Both Acrobat executable names are in the list because some users have Acrobat and some have Reader.
This was tested on Windows 7 Pro 64-bit.
