I have a very similar problem.
I started Island Rum, it attempted to update, and then closed. Same thing when I tried again.
When I looked, there was an "Island Rum" folder inside my "Island Rum" folder.
Running the "lower" Island Rum made it update properly. But CoH still doesn't start when I click start.
The problem started sometime in the last week, so I'm not sure if it has to do with the June 30 update.
I also tried reinstalling CoH and a freshly downloaded copy of Island Rum from scratch, but same thing happened.
Using Ubuntu 18 x64