# DD-PPO not working on Win10

**URL:** <https://discuss.ray.io/t/dd-ppo-not-working-on-win10/1937>\
**Category:** RLlib\
**Created:** [April 27, 2021, 7:15pm UTC](https://discuss.ray.io/t/dd-ppo-not-working-on-win10/1937 "2021-04-27T19:15:51Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Denys\_Ashikhin](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/denys_ashikhin/32/58_2.png) [@Denys\_Ashikhin](https://discuss.ray.io/u/Denys_Ashikhin)\
**Post date:** [April 27, 2021, 7:15pm UTC](https://discuss.ray.io/t/dd-ppo-not-working-on-win10/1937/1 "2021-04-27T19:15:51Z")

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Hi all,

I’ve been trying to get the built in DD-PPO trainer working and run into the following issue:

```auto
  File "C:\Users\denys\AppData\Roaming\Python\Python38\site-packages\ray\thirdparty_files\psutil\_pswindows.py", line 681, in wrapper
    raise convert_oserror(err, pid=self.pid, name=self._name)
psutil.AccessDenied: psutil.AccessDenied (pid=72)

```

I have tried running the command in administrator CMD to no avail. Is there any fix for this?

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**Author:** ![rliaw](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/rliaw/32/24_2.png) [@rliaw](https://discuss.ray.io/u/rliaw)\
**Post date:** [April 29, 2021, 3:11am UTC](https://discuss.ray.io/t/dd-ppo-not-working-on-win10/1937/2 "2021-04-29T03:11:14Z")

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@Denys_Ashikhin thanks for making this issue. Could you post the full stacktrace and repro on Github?

Thanks!

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<div class="post-metadata">

**Author:** ![Denys\_Ashikhin](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/denys_ashikhin/32/58_2.png) [@Denys\_Ashikhin](https://discuss.ray.io/u/Denys_Ashikhin)\
**Post date:** [May 3, 2021, 11:21pm UTC](https://discuss.ray.io/t/dd-ppo-not-working-on-win10/1937/3 "2021-05-03T23:21:36Z")

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Sorry for the long delay, I had wanted to exhaust all the possible test cases. I did make open an issue at: [DD-PPO not working on Win10 [rrlib] · Issue #15623 · ray-project/ray · GitHub](https://github.com/ray-project/ray/issues/15623)

That being said, I have managed to get an almost identical setup working with an external env for my game with a **PPO** trainer but the synchronous overhead tends to bottleneck things too much (mainly because the server I have is upload bandwidth starved) so remote clients take too long to update. This is where I was hoping that DD-PPO would have less internet overhead and if it it’s the same, as long as the updating of values from the main process is non-blocking to the main actor playing the game, that would be perfect.

Please let me know if my hopes/understanding of DD-PPO here is flawed!

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**Author:** ![sven1977](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/sven1977/32/53_2.png) [@sven1977](https://discuss.ray.io/u/sven1977)\
**Post date:** [May 4, 2021, 9:32am UTC](https://discuss.ray.io/t/dd-ppo-not-working-on-win10/1937/4 "2021-05-04T09:32:59Z")

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Actually, @Denys_Ashikhin , this is a known issue and unfortunately not captured with a proper error message. DD-PPO uses `torch.distributed.init_process_group` which throws an error on Win.  
I’ll add a check to DD-PPO’s validate\_config and at least provide a meaningful NotSupported error message.

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<div class="post-metadata">

**Author:** ![Denys\_Ashikhin](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/denys_ashikhin/32/58_2.png) [@Denys\_Ashikhin](https://discuss.ray.io/u/Denys_Ashikhin)\
**Post date:** [May 4, 2021, 6:43pm UTC](https://discuss.ray.io/t/dd-ppo-not-working-on-win10/1937/5 "2021-05-04T18:43:54Z")

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This means that unfortunately the fix would have to wait until PyTorch fixes it on Windows right?

As a follow up, would it be enough to make a Linux VM on to run the policy\_server, while the clients run windows (for DD-PPO)?

Also, I have had trouble getting APPO working as well - is that related to windows incompatibility or should I open an issue for that?