After installing OS 10.13.4 on my mid-2010 MackBookPro (with an SSD) I made one sparse image bundle, which is working fine. However, using Disk Utility,I am now unable to make any additional disk images of any type, on my internal drive (APFS) or on any of my external drives (HFS). Depending on the specifications of the disk I'm trying to make, encrypted, non-encrypted, etc, I get varying error codes, always accompanied by "Permission Denied." I've tried every type of image and every possible combination of size, file format, etc. Absolutely nothing works.