Apps open multiple times

Installed Ubuntuunity 20.04 today. Boot after install was fine no problems.Now everytime 20.04 is booted the desktop flickes for a few seconds. When it settles down when I open any app it keeps opening a multitude of that app until everything is frozen. The only way to solve this is to power down the computer then power up again.
This is my wife’s computer with Windows. There is no problem with Windows.
This is not a dual boot. I installed on an external drive because I didn’t want to install it on her computer.
I had this problem in Ubuntu 14.04 I believe but I don’t remember how I solved it and I haven’t been able to find anything on the net.
I am hoping someone here has an answer.