Hey Ron,
I don't know whether this may shed any light at all.
I 'opened for editing' Mick's <kuid:287284:100270> Aus Relay Box Modern to see if there was something that may need updating.
The .texture.txt files are not listed and it does show Trainz build 3.1 as Installed Payware,.. and in exiting,... I used 'Revert if Unchanged' which still shows as 'No errors or warnings'.
So the asset is still usable.
Is it possible that 'Committing' the asset instead, might cause it to raise the error and warnings.
I've used much older assets in my route before. In fact in my latest route, of 2218 assets there are 357 with Trainz Build 1.3 and still functioning.
I like Mick's work, so if it can't be rectified at your end, just delete it. Mick also has a built-in scenery asset <kuid:287284:100269> Aus Relay Box Modern which could be used as replacement.
Cheers,.
Roy