SteamCMD failing to download mods in bulk

[Hypocrita]

Hopefully this is the place to ask this, if not, my apologies!


I'm developing a program that, among other things, passes commands to SteamCMD to download workshop mods in bulk. I've had a number of users report that they're getting "Error! Downloading item failed" every time they try to use the program.
One person reported that even the content folder in SteamCMD's workshop folder wasn't being created.

Frustratingly, I've so far failed to recreate this behavior on my machine and am unsure where to even begin to solve this issue (everything works fine for me and refuses to break.) Up to now, Google sadly has failed to give much insight, and what documentation I've found for SteamCMD is sparse and rather unhelpful concerning this issue.

More details:
The command to download mods follows this format: <user-selected steamCMD install folder>\steamcmd.exe +login anonymous +workshop_download_item <game ID> <mod ID 1> +validate +workshop_download_item <game ID> <mod ID 2> +validate +quit
The workshop bit just repeats for however many mods the user wants to download.

The program I'm developing launches an unelevated/non-admin command prompt to execute this command.
This is not for a server, if that matters, all contained to one person's machine.


If you need any more info, just let me know. =-)
Thanks!

[Hypocrita]

Seems like this is related to anonymous login. Initially it seems like requiring login fixes this.