Rawtherapee and gimp

I, I have a curious problem with my Rawtherapee and gimp instalation. So, I work in ubuntu studio 16.04, Rawtherapee 5.and Gimp 2.10.8
When i try open one image with the external editor in Rawtherapee, Gimp gives me a message to tell folder or file do not exist, but both exist, the tmp folder and (inside) the tiff image.
When i try open the file directly in gimp, i can find the folder, but gimp do not find anything, only .snap folder.
Any one have idea what is this.
Also if i try to open a raw file in gimp, thw software tells me i need one of to, Rawtherapee or Darktable. But I have both installed and gimp do not open.
Can you help me?

Did you install gimp from a snap package? If yes, you’re probably encountering snap sandboxing and you should try disabling the sandbox.