Crankshaft pulley bolt thread gone

[Jvdv23]

I have a (big) issue.

As you can see in the picture the thread on the bolt for the crankshaft pulley is gone (top of the bolt). If you look at the bolt, what would this mean for the thread in the crankshaft? Is it gone as well or is the material from the bolt softer and left in the crankshaft?

Any ideas how to get a new bolt fitted in the crankshaft?

Many thanks for your ideas.