This error occurs when the path for the output model does not exist. This is an error that happens at the compile stage and will happen if you are compiling straight from WWMT or by compiling manually from the batch file.
This error usually indicates Steam did an update or you are working with a mod that doesn't use the Steam VProject setting. Read the fix here.
Some of the MacroScripts in Wall Worm now have a default secondary action when executed with the SHIFT key held down.
Information on why keyboard shortcuts using the SHIFT key open the online documents for the function rather than running the function.
This error occurs if you are trying to compile an image that has a dimension that isn't a Power of 2.
Anvil embeds reference to a script in your 3ds Max scripts folder. If that file is missing, there can be an error.
Anvil embeds some scripts for scene startup to protect displacements from being invalidated via improper manipulation. Older versions of Anvil referenced a file that could cause an error if missing.