Hello @pwinata,
I have also experienced something along the same lines.
I will have a solution, let's call it version 1.0.0.0.
If I wanted to export that as a managed solution the environment will automatically put it to 1.0.0.1.
Now if I want to keep it as 1.0.0.0 when I change it and export, the environment hangs, as you mentioned.
My workaround is export it as unmanaged with version 1.0.0.1 and then once it's exported I then export the solution with 1.0.0.1 and change it back to 1.0.0.0 as a managed solution and it allows me to do it. Strange.
I raised a ticket with Microsoft and the support engineer was excellent. He said the product team will include a checkbox to let us choose not to increment if we so wish. So hopefully that will come soon.
Thanks,
Garry