Before you read i want to let you know that the version 1.14.4 is not version that has a bug in it. I just had to choose one to continue on because you can´t choose a Forge version... 

I was trying to load a regular Forge version (1.8) to play and test a mod. However there is a problem. If I click on the Play button it may seem as it would load but in reality when the loading bar is full, the launcher closes and opens just a few second later with a message. It says something like: "This version cannot be loaded. Sorry for the interruption." But the thing is that I didn´t even do anything special. All I did was clicking the Play button. (If you are wondering wich mod I used then here you go: Lucky Blocks Mod)