Lost hard drive space to Boot Camp
If Disk Utility (booted to Internet Recovery Mode) can't repair the error, there is nothing else than booting to your main volume, backing up everything to an external disk and after rebooting to Recovery Mode deleting the Logical Volume and re-adding a new one. 

If that fails you have to delete the Logical Volume Group as well. Create a new one - including a new Logical Volume. 

Restore your backup and boot to your main volume again.

Finally enable FileVault and encrypt your main volume.