LineageOS: Phone and Contacts crash
If you have the cynogenmod zip file somewhere stored then I think it is very easy to restore it. Just extract the cynogenmod on your computer and go to system->apps and copy the apks which are not working (eg.Phone, Contact in your case). Now also extract the nightly build which is giving you errors and go to system->apps and find the phone.apk and contacts.apk and delete it. Now just paste those apks which you had copied from CynogenMod and compress the modified Lineage OS in zip format. Now you are all done. Flash the newly created zip file and comment here if it worked (which is going to work in most case).