When you SQL Agent Job running as ProxyUser rather than default AgentService account then you may get following error.
System tried to search for the following license types [SSIS_PP_ENT, SSIS_PP_PRO, …….., SSIS_PP_TRIAL] under the following path [C:\ProgramData\ZappySys\SSISPowerPack] but no valid license found. Additional information >>> LoggedInUser=MYDOMAIN\MYSERVICEACCOUNT >> RunAsUser=MYDOMAIN\MYSERVICEACCOUNT >>> Path access=True >> >> TempFolder=C:\Windows\TEMP\ [Read/Write=OK,OK] >> License Files Scanned  ==> C:\ProgramData\ZappySys\SSISPowerPack\SSIS_PP_TRIAL.lic.130498499674709531 [Read=OK], . Please read this link for more information => https://zappysys.com/links/?id=10021. Inner error=> License type [SSIS_PP_TRIAL] not found or its expired. You are running TRIAL build, if you have paid license then you must download full version.
Possible cause of this issue could be your Proxy User Account is trying to access Temp directory of Parent (i.e. SQL Agent Service Account). And by default one user cannot access directory under user profile unless you are an admin. Each user profile has its own temp directory which is usually located here %USERPROFILE%\AppData\Local
To fix such issue first try to activate license under normal user account. Perform following steps.