I was trying to install the latest version of mono... but now somehow my package manager is broken with the error: Error: Broken Count > 0.
When I try to install any package using the software manager GUI I get an error:
"Unable to install 'Synaptic Package Manager': Error while installing package: trying to overwrite '/usr/lib/mono/msbuild/15.0 which is also in package msbuild-sdkresolver 1"
When I try and do sudo apt --fix-broken install
I get the error:
Trying to overwrite '/usr/lib/mono/msbuild/15.0', which is also in package msbuild-sdkresolver 1:15.4+xamarinxplat.2017.09.14.16.14-0xamarin2+ubuntu1404b1
Errors were encountered while processing:
/var/cache/apt/archives/msbuild_1%3a16.3+xamarinxplat.2019.08.08.00.55-0xamarin2+ubuntu1804b1_all.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)
And this results in a general package system broken error when trying to run the software updater graphically:

How do I fix my mono install and package manager?