The initial problem in our scenario was trying to deploy an application via SCCM, which was showing as "Past Due - Will Be Retried" in Software Center and had a Failed status with error code 0x654(1620).
I checked the AppEnforce log at C:\Windows\CCM\Logs on the client computer, and it showed an incorrect network path on the command line being run for the application.
I discovered within the deployed application's .msi-installer settings in SCCM that the Content Location was blank, and the Installation Program specified was incorrect.
I created a new deployed application as a test, making sure the Content Location contained the correct path, and the Installation Program contained the correct .cmd file we created for the install.
I added the machine in question to the collection for this test app, and verified the app showed up in the computer's Software Center.
However, a new problem arose - the new test app kept saying "Past Due - Will Be Retried" in Software Center. If I tried to initiate the install from Software Center, it would fail, showing Past Due status again. This time the failure code was 0x654(1612). I also confirmed that the application woud install if run manually from the ccmcache folder. After some research and looking at .msi error codes, I found a solution online suggesting removing an associated registry entry to the install file.
I navigated to the registry, opening it as administrator, and searched for the program in question's GUID. It showed up under a SourceList key, sure enough listing the previous incorrect path for the install.
SOLUTION - original solution can be found on Mick's IT Blog (see Sources link at bottom):
I backed up the registry just in case, and then deleted the GUID folder of the full path containing the SourceList key:
HKEY_CLASSES_ROOT\Installer\Products\<GUID>
I re-initiated the install from Software Center, and the application installed successfully.
SOURCES:
http://mickitblog.blogspot.com/2015/10/sccm-deployment-with-error-1612.html
https://msdn.microsoft.com/en-us/library/windows/desktop/aa376931(v=vs.85).aspx