Saw this issue in 2020. Going to calendars to unsubscribe doesn't work because I do not have tax cut or HR Block as a calendar subscription. Tried Lawrence Finch solution: settings/Password & Accounts/suscribed calendars; however, my OS version 11.4 doesn't have these options. Any suggestions? Thanks. Will be updating to 11.5.1 tonight.
iMac, OS X 10.10
One might have picked up a piece of Malware / Adware ?
For peace of mind and computer suggest downloading from a Trusted Developer and Respected ASC Contributor the application Malwarebytes for Mac. It is free or paid for added features. Run the Application and it should remove the malware / adware. Once done, restart computer and test.
There are no known Viruses in the wild that self replicate and affect macOS. There are Malware and Adware that does affect macOS and are often times downloaded as part of an Application from Third Party UnTrusted Site and get installed along with the Application.
That you. I have Avast and will run it. Hope that’s good enough.
Avast get that sv software off ASAP as per developer instructions. Worthless and causes havoc. It can also corrupt the OS
use the suggested application
Cannot Verify Server Identity version.taxcut.com
