During the recent Mass Windows 10 application testing, few of the SCCM Application deployments failed with Exit code 1. “The software change returned error code 0x1(1).”
The content was already distributed to the local distribution point, and everything appeared to be in order. Looking further into AppEnforce.log showed some interesting signs stating “The content path is not specified for DeploymentType …” and “Content is assumed to be locally available“, followed by Unmatched exit code (1) is considered an execution failure.
SOLUTION: To fix the issue, simply update the content on the DP, refresh the machine policy on the local client, and you should see the content starts to download followed by triggering the installation.