Time Machine cannot start the backup

Understand, we are all working Remotely from all around the world. 

Therefore, we do not have the On-Hands experience the User ( you ) has with this computer.

The next best thing for us to having a semi - actual On-Hand experience  with this computer is to follow the steps below

Download the Application Etrecheck directly from the Developer. 

The application is free or paid from added features. 

It will take a Snap Shot -  both the hardware and software.

 The Report will Not Reveal Any Personal Information. 

Post back the Full Report - copy and paste - using the Additional Text Icon ( 3rd Icon to last )

We can have a look at the report for possible issues and may have possible suggestions to resolve the issues.

Description: Time machine has suddenly stopped working on my MacMini... this is the message I get:;An error occurred while starting the backup. Antivirus software may be preventing Time Machine from writing to the backup.

Major Issues:

Q - Unsigned files - There are unsigned software files installed that could be malicious and should be reviewed.

A - This is covered later in this report 

Hardware Information:

  Mac mini (M1, 2020)

 Q -  disk4 - BUFFALO HD-GDU3 3.00 TB

  External USB 5 Gbit/s USB

    disk4s1 - EFI [EFI] 315 MB

    disk4s2 - B************i (Mac OS Extended (Case-sensitive, Journaled)) 3.00 TB (2.54 TB used)

A - Generally in Monterey,  the Time Machine Backup needs to be in the APFS Drive format

A - Also, the drive is getting a little low on Empty Space. TM Backup, in theory should delete the oldest Snap Shot to make space when required. Sometimes it does not. Should that happen, suggest getting a New External Drive with 2 1/2 or larger Drive Capacity and start a New TM Backup regime. Keep the Older Drive in a Safe Place incase you every need to get some back again.

Q - System Software:  macOS Monterey 12.5 (21G72) 

A - Current version of Monterey as of Aug 17, 2022 is Version 12.5.1 witch fixes the security flaw found and in the News everywhere.

Q - CleanMyMac X.app

A - CleanMyMac aka “ BrickMyMac “  This application may have been installed in the attempt to resolve the TM Backup issue or maybe not. Either way, it needs to be Removed by the Specific Instructions of the Developer. Earlier in this Report and issue of AntiVirus Software was blocking the TM Backup for starting. Think the CMM was really the culprit 

Any Third Party Applications that will interfere with the normal operation of the OS,  is an invitation for disaster and comprising the Operating System

Certain Applications maybe available on the Apple Apps Store - this only means the Developer is prepared to pay Apple a portion on each sale. What the Application may do to the computer is up to the User to check this out before purchase

Any of the below should be removed as per Developers Instructions

This will include CleanMyMac 

 Q - Running app: /Library/DropboxHelperTools/Dropbox_u502/dbkextd

    Details: Domain name invalid - possibly malware

A - This is worrisome and bears serious consideration and attention.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.

Q - Plugin: /Library/Internet Plug-Ins/Silverlight.plugin

A - Outdated and no longer used or supported by the Developer - remove 

Q - Preference panel: ~/Library/PreferencePanes/Perian.prefPane

A - Outdated and no longer used or supported by the Developer - remove

Thank you for the Report.

I will dissect it, in detail,  and get back to you shortly