SP 48 Husky Stack kuid2:45324:300020:1 works fine for me in T:ANE SP3.
MWPX 89ft flatcar kuid:506034:434346 works fine.
89ft Autorack SP kuid:334896:200034 is fine.
I also checked numerous other assets by Joe (socalwb909) and they all work fine.
I would check the config.txt file and ensure you didn't do something different.
Is the range too large?
Try setting it down to 10 numbers and see if that works. If it does increase the range to about 50 or so. Having 10,000 each 89ft flatcars, wellcars, and autoracks is a bit much. It maybe that the ARN is just kicking out and dying because the range is so huge. This was a problem with TS12 where we actually got a script error regarding this.
You can enable script error reporting (red bug thingy), it's off by default now, by clicking on Dev tab in the Trainz settings on the Launcher and choosing Show script exception notifications.