To activate 3D Studio Max 7 in linux, you have to install a second version in a virtual machine (e.g. virtualbox), activate it there and then transfer the license to the linux-installation. Since the activation-wizard is html-based it doesn't work under crossover because of the missing internet explorer. With the portable license utility, shipped with 3DSMax, a workaround is possible this way:
Open the "Portable License Utility" of the 3DSMax-version installed in linux. The identification code is shown at the bottom. Write it down for later use.
Open a terminal-window and type "echo $HOSTNAME", the terminal will answer with the computer-name. Write this one down as well.
Now launch the license-utility of the activated 3DSMax in virtualbox. Click on "Computers" and then on "Add". Type the previously mentioned identification-code as well as the computer-name in the two fields and hit OK. The linux-version of 3DSMax is now added to the utility's list in virtualbox.
Afterwards click on "Licenses" and then on "Export License...". The now upcoming list is reading the linux-installation as well. Choose it and click on "Browse" to set the target-folder. You need to have a shared folder to export the file to your real harddrive outside virtualbox. If you don't know what it is and how to set it up, click on "Devices" and on "Install Guest Additions" in your virtualbox-window. Also read the helpfile (sub-topic shared-folders) to finally set-up such an exchange-folder.
Once a shared-folder is chosen, click on "Transfer License" in the license-utility-program.
A success-notification should appear and you can close the utility afterwards. The virtualbox-3DSMax is now locked. The license-file can only get imported with the linux-3DSMax-utility now. If you want to unlock the virtualbox-version at a later time, you will have to generate an export-licence with the linux-version in a similar way. Only one version can be unlocked at a time.
In 3DSMax-linux' license-utiliy choose "Import License" and then on "use transfer file". Click on Browse and navigate to the shared folder, holding the previously exported license-file. Click on Import. If request pops up with the text "A computer entry with the same name already exists." choose "Replace existing entry" and click OK.
Voila - 3D-Studio-Max-Linux is activated now. You can erase the virtualbox-version afterwards as it can't get activated anymore.
Edit:
If 3D Studio 7 crashes in linux directly after the splash-screen: Navigate to the 3D-Studio-installation-folder and open the subfolder stdplugs. Remove the file cmbtex.dlt. 3D Studio shouldn't crash anymore afterwards.