The 127 issue where there are a lot of them is a bug as a large number of my DLS assets were showing as 127 a couple of months ago. DBR and reboot and all back to normal. Curiously initially on list asset versions there were none despite the originals and updates being on the DLS, I have concluded rightly or wrongly it's a server issue of some kind.
Other than a genuine 127 or the above problem, often it's actually a kuid2 asset uploaded where the creator missed off the version number, as in kuid2:12345:12345 instead of kuid2:12345:12345:1, only on old kuid assets pre 2009 I believe and you can install them and edit the config and verify the version is missing of the end of the kuid, that unfortunately won't fix the problem though as the DLS is transfixed on it being a 127. Newer Trainz versions I'm pretty sure nipped that one in the bud.