If you check my code example, you will see that I'm refreshing the second session before committing. I was expecting that this would prevent the exception but it is still thrown. This is the part I don't understand. Maybe one session cannot refresh changes from another one?

Support resolved our problem. Contact them

You are correct. When I try to open URL directly, I get this error message:WEB-530009 Access denied.Can you tell me where exactly can I raise a support ticket?

Everything else is the same. No preview. There is no error message, just this default thumbnail.In Brands, system doesn't save uploaded image and it always looks like this: