Looks like steel bolt into aluminum and has stripped aluminum into the bolt threads. Helicoil is a good fix . Seems you will need oversize drilling and mandatory perpindicular (90 degree) drilling. If you (or a friend) are good with tools you might be able to tap to the next size bolt directly into the aluminum. The stripping may be the relsult of over tightening. Use a torque wrench and the proper value for the unlubricated ( or lubricated ) bolt. See chart this forum.