[ubuntu] Ubuntu 16.04. After upgrade Manager.IO is gone

I'm working as a volunteer for a philatelistic society. I keep the financial accounts up to date with Manager.IO, installed on Ubuntu 64bit.

The computer is a 7 year old desktop. I installed Ubuntu 15.10 without any problems. Since that time I moved all the accounting to this desktop. Manager.IO also gave no problems at all.

Today I upgraded to Ubuntu 16.04. And now Manager.IO has disappeard from the computer?????

I did the online upgrade. The process went smooth and did not give any problem at all. All the files seem untouched. Except...
Manager.IO has disappeared from the Starter, also from the start page, the search does not find the application. The file browser search does not find anything either.
I have tried to reinstall the application, freshly downloaded. That did not work; the program did not install.

Now I need to solve several issues:
1 Where do I find the "missing" Manager.IO application files, if still present?
2 It seems that the upgrade broke a link or something, if so, how to locate and fix it?
3 How to get the application back on the computer, now that installation does not work?

Can somebody give me some directions to try solve this? Any help is appreciated.

Thanks,

Daniël Noest