MacOS High Sierra Messages app unread icon reappearing, causing system to hang

I see nothing in your Report that gives me a clue to the cause.

Whenever I have unusual behavior like this, I reboot in Safe mode, then restart normally.

Safe mode startup is a very useful fix-almost-all-OS-problems tool. It does a Repair disk during the boot process, and is faster than booting from an external drive to run DU-Repair Disk on the internal drive.

Disk Utility is an app native to the OS. When it or any other native app misbehaves, you should concentrate your repair efforts on the OS. When booting in Safe mode, all 3rd party additions are "disconnected", and only the base functions of the OS are activated.

My second effort at fixing this problem would be to re-install the latest Combo update. This will do a similar thing - revert any intentional or inadvertent changes to the OS back to the default state, without affecting your data and most settings.

Third, if you have a relatively current external backup clone, you might try booting in that drive to see if the DU problem persists. If the problem is not there, you can clone that drive to the internal drive and restore current data from Time Machine.

Those folks that are Terminal-savvy may offer better solutions.

Hope this helps.

Here is a method to hunt the kext which may cause you a hang system.

1. Boot in safe mode & make a capture of the minimal safe set of extenions loaded with:

   mkdir ~/tmp
   kextstat >~/tmp/safe.kextstat
   

2. Boot in normal mode & make a capture of the full set of extensions loaded with:

   kextstat >~/tmp/full.kextstat
   

3. Compare them:

   cd ~/tmp
   diff full.kextstat safe.kextstat
   

   and from this difference, which is including the faulty kext, extract the culprit by checking its installation date:

   ls -dlT /System/Library/Extensions/<extension_folder_name…>
   

   The faulty extension will be the one installed at the time of the start of your kernel hang.

   Beware: the extension_folder_name… is not the extension name as displayed by kexstat.

   Here is an example:

   on_my_mac$ kextstat | egrep 'Addr|ThunderboltDPA'
   Index Refs Address            Size       Wired      Name (Version) <Linked Against>
      70    4 0xffffff7f8125e000 0x8000     0x8000     com.apple.driver.AppleThunderboltDPAdapterFamily (1.8.2) <45 9 8 5 4 3>
   on_my_mac$
   

   is coming from:

   on_my_mac$ cd /System/Library/Extensions
   on_my_mac$ ls -dlT AppleThunderboltDPAdapters.kext
   drwxr-xr-x  3 root  wheel  102 Aug 31 05:39:06 2011 AppleThunderboltDPAdapters.kext
   on_my_mac$
   

4. Make a backup copy of the suspected extension:

   mkdir ~/Extensions_backup
   cd /System/Library/Extensions
   /usr/bin/sudo mv faulty_extension_folder_name ~/Extensions_backup
   

   and test this system with one missing kernel extension:

   reboot
   

5. If it is OK. You got the right culprit.

   If not. Just reverse step 4, reboot and repeat from step 4 to test the next potential extension.