usually you can find a clue to the issue if you run

/usr/local/munki/managedsoftwareupdate -vv

L
might also want to try the munki channel in macadmins slack and/or munki google group, but after you run the above command ( I'm sure someone will ask for the output)

I did run that but the only error I got was a 404 with it not finding the icon for the package.

I did some more research and posted on the google group and posted the following:

Hello,

I come from a casper environment but one of our sites uses munki. I'm pretty new to munki and it was setup by my predecessor.

The issue is when I imaged computers it looks like some of the packages didn't install. No big deal I'll just check for updates with the software center.

I click check for updates and it finds 5-13 packages that need installed. I click update and it either sits and does nothing, or "finishes" quickly, but only downloads the packages to /Library/Managed Installs/cache" and doesn't install them. I haven't changed anything that my predecessor did other than use autopkg to update a few of the paackages. i.e. chrome from version 30 to version 60.

One of the errors I find is ""hdiutil attach failed - Operation timed out" While mounting". But I can manually mount the dmg and install the software.

If I look at the "Install.log" on one of the computers is shows the following errors: Flash, Shockwave error return code 1. Google Chrome failed with error return code -1.

Any help would be appreciated.

@Asnyder come over to the macadmins.org Slack, there's a #munki channel in there.