Welcome to the forum, @Xavier_Avsec 
That sounds like there’s a 3rd party application interferring with the game.
Did you check that none of these applications and processes is running when you’re playing Stonehearth? : Crashing on start? Read this! UPDATED October 18, 2016
What are your system specs (CPU, RAM, OS, Graphic card)? Are you using any mods?
Could you right-click on Stonehearth in your Steam library, click on Properties, Local Files tab, Browse local files? It should open the folder where the game files are. Do you see any crash.dmp or crash.zip file after you get a crash in 64bit inside that folder? If so, could you upload it so that devs can take a look at it?
The stonehearth.log after the game crashes would also be useful (it’s a text file in that same folder).