для 6-го макса есть маленькая заплаточка - ftp://ftp1.discreet.com/web/support/3dstudio/avibmi.zip
Updated AVI.bmi for correcting the AVI file save error.
This update services the save to AVI file format feature for 3ds max 6 or 3ds max 6.1 English. The English update can also be applied to localized installs of 3ds max, but the AVI specific dialogs will appear in English.
To install, unzip avi.bmi to the \3dsmax6\stdplugs folder