ThingWorx Exception 4: File download fails due to file deletion on the ThingWorx Platform before agent downloads file
This exception appears if platform-initiated file downloads are not downloaded by an asset. A symptom could be if the file was deleted from the repository before the agent downloaded the file.
Here is a scenario that will result in this exception:
1. Start ThingWorx Platform.
2. Start eMessage Connector.
3. Enqueue a file download by calling the File Transfer Subsystem.Copy service and set queueable to true.
4. Delete the file from the SystemRepository of the ThingWorx Platform before the agent pings to check for download egress.
5. Start the agent that will poll and check for download egress.
In this scenario, the download fails when the eMessage Connector attempts to calculate the checksum of the file from the SystemRepository. However, since the file no longer exists, the download fails. The error explains that the file was not found:
...
Unable to Invoke Service GetFileChecksum on SystemRepository :
/ThingworxStorage/repository/SystemRepository/download.txt
(No such file or directory)
... error executing APIRequest Message: ...Unable to Invoke
Service GetFileChecksum on SystemRepository :
/ThingworxStorage/repository/SystemRepository/download.txt
(No such file or directory),
sending ERROR ResponseMessage to caller!
To resolve this error, restore the file to the proper location and run the service again.