The new version is a bit more picky about textures. There are a few things here that occurred.
I ran into a few of these assets that had that error. The problem was the asset or texture was corrupted all along and wasn't displaying properly in previous versions even though it wasn't reported as an error verbosely, but was mentioned in the logs. (I'll explain this afterwards).
I found this out by opened up the asset for editing to ensure that the texture was in fact there and in place. The textures are there, but when I opened them up in Paint.net, they didn't display at all, and one actually produced an invalid file error. For a couple of the assets, I was able to download fresh ones. For some others, the downloads had the problem as well so this was the issue all along.
When I saw this error initially, I checked the assets in Build 106618 thinking this was a beta-version problem. The asset loaded up fine and appeared fine. I then opened up the logs - Developer menu on Launcher --- Show logs. This displayed a red ! and the same error number you received. This meant the texture wasn't being displayed in this case - a hidden object from my view, but the asset was opened anyway by horsing it through the system. This is great for showing the models, but it means there's extra overhead which can cause performance problems like awful stutters when the asset is viewed or loaded.
A few of the other assets I checked, however, couldn't load up at all so they were trashed from day one.
Things to do:
Delete the asset and reinstall from CDP files, or from the DLS. Sometimes, reinstalling this way will fix the problem with the asset.
Check that the texture is there and is spelled correctly and the SAME texture is mentioned inside the .texture.txt file. (Yes, I have seen the texture spelled wrong inside the texture.txt file, and the texture.txt file have typos in it, like a space for example in the name).
Try changing file formats. Sometimes the author may have made an error and used a bmp file and should have used a .tga. I have actually gotten lucky doing this. It means editing the related .texture.txt file and updating the image-file extension listed in the .texture.txt file.
If all is there as it should be, you can try PEV's PM2IM utility. Set this to open IM files in the options. This will sometimes fix texture problems related to being in an incorrect material slot when the asset was created in Max or GMax. I also found opening up the texture in Paint.net, you can use your favorite image editor to do the same, and resaving it out again sometimes works as well.
Hope this helps.