OK, I've just fixed my own problem, well done me. I checked the MO filetree for AQWM and sure enough, the folder and file structure was there, but all files were 0 bytes in length. I redownloaded the mod (installer version) and installed via MO, same result. I then repackaged the mod choosing the STEP Core recommended version (main roads only, hi-res) and installed the new archive. It worked fine. Is this a problem with AQWM installer? Can anyone confirm? The latest version of the mod is from 2012, so it hasn't changed since STEP 2.2.8. I'll go through other STEP Core mods to make sure it didn't happen anywhere else. So far it doesn't seem to be installer-dependent (as SMIM installed fine).