I downloaded and installed the OS 10.11.5 update from App Store. It weighs in at 907 MB and installed very quickly. The dialog box estimated 20 minutes to complete the installation but the actual time was closer to 5. All seems well.
Jon
macOS 11.7.10, iMac Retina 5K 27-inch, late 2014, 3.5 GHz Intel Core i5, 1 TB fusion drive, 16 GB RAM, Epson SureColor P700, Photoshop CC, Lightroom CC, MS Office 365
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