I just bought an old license for Softimage 5.11 . But if i want to activate it softimage crashes. Whats wrong?

EDIT: If i type in a wrong code it doesnt crash. But i have no license server tool or something like this. If i google my error they say i have to do something with the license server tool

The XSI Essentials 5.11 and XSI Advanced 5.11 versions required a license server for activation. The license servers don't exist for these anymore, that was back when Avid owned Softimage. Those versions are 7 years old now and XSI Foundation 5.11 is the only one that can be activated with just a license key anyway. You should probably try to get your money back. All you need for asset creation and export to SWBF2 is Mod Tool 7.5 and ZE Tools, both are free.

It is xsi foundation. How can i activate it without a server? And if its not possible i think than i'm going to crack it. I bought a license so its not illegal or?

I already told you XSI Foundation 5.11 requires only a key, not the license server. If your key doesn't work then there is nothing anyone can do for you. This version is dead to the company that now owns Softimage. I don't know who you bought a license from, but you should try to get a refund. We also don't discuss software cracking here, this will result in your Gametoast account being banned.