Unable to open manager after upgrade

I upgraded today. Manager disappeared. Re-installed Manager. I see and click on the icon. There is no reaction at all. Using Ubuntu 14.04. The “Your topic is similar to…” is not similar.
I then uninstalled and installed from Manager site. Now clicking on the Manager icon I get this message.

System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary.
  at System.Collections.Generic.Dictionary`2[System.Guid,System.Type].get_Item (Guid key) [0x00000] in <filename unknown>:0 
  at ManagerServer.Serialization.GetTypeByGuid (Guid guid) [0x00000] in <filename unknown>:0 
  at ManagerServer.Objects.Get (Guid entityId) [0x00000] in <filename unknown>:0 


Please search the forum before posting new topic.

This topic will help:

Make certain you upgrade mono for Ubuntu first.
See notes here Ubuntu

Here are command lines, in this order.

sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF
echo “deb http://download.mono-project.com/repo/debian wheezy main” | sudo tee /etc/apt/sources.list.d/mono-xamarin.list
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install mono-devel
sudo apt-get install mono-complete

Where did you download Manager from? The error indicates you’ve installed some older version. Make sure to go to https://www.manager.io/desktop/download and download DEB file for Ubuntu from that page.