Send to Unreal - No instance of UnrealEditor found - macOS Silicon (M2)

[splittheatom]

Addon: Send to Unreal

Steps to Reproduce the Problem:
-> When clicking "Export -> Push Assets", Blender returns an error saying that no instance of UnrealEditor was found.
I have made sure Remote Execution is on in Unreal, and even changed Multicast bind Address to 0.0.0.0
I have also made sure the Plugins are activated.
I have tried on different Unreal projects, and on version 3.3, 3.6 and 4.0 of Blender, without success

Error Log: (where can I find the full error log?)
OS: Mac OS Sonoma 14.2
Addon Version: Send to Unreal 2.4.3
Blender Version: Blender 3.3 and Blender 3.6
Unreal Version: 5.3.1

[RWOverdijk]

Same message here.

• Blender 3.6.5
• UE 5.3.2
• Send to Unreal 2.4.3
• Mac OS 14.1

It did work before, but I can't remember the version combination of all the tools.

I tried send to unreal 2.4.1, 2.40, 2.2.0 and 2.1.0 (still had them in my downloads folder lol) so I don't think the issue is in the addon itself, but a compatibility issue with either UE or (my bet) Blender.

[BoomRaccoon]

Addon: Send to Unreal

Steps to Reproduce the Problem: -> When clicking "Export -> Push Assets", Blender returns an error saying that no instance of UnrealEditor was found. I have made sure Remote Execution is on in Unreal, and even changed Multicast bind Address to 0.0.0.0 I have also made sure the Plugins are activated. I have tried on different Unreal projects, and on version 3.3, 3.6 and 4.0 of Blender, without success

Error Log: (where can I find the full error log?) OS: Mac OS Sonoma 14.2 Addon Version: Send to Unreal 2.4.3 Blender Version: Blender 3.3 and Blender 3.6 Unreal Version: 5.3.1

You have to set multicast bind address to 127.0.0.1 if you are on UE 5.3

[RWOverdijk]

You have to set multicast bind address to 127.0.0.1 if you are on UE 5.3

I don't see how that can be true. 0.0.0.0 (while not ideal for local only) should include the loopback (127.0.0.1) interface. Meaning if 0.0.0.0 doesn't work, 127.0.0.1 also doesn't work. But maybe there's something else going on that I don't know.

[BoomRaccoon]

I don't see how that can be true. 0.0.0.0 (while not ideal for local only) should include the loopback (127.0.0.1) interface. Meaning if 0.0.0.0 doesn't work, 127.0.0.1 also doesn't work. But maybe there's something else going on that I don't know.

All I can tell you is that I am on windows and had the same issue. Can't remember how I got the idea but changing it to 127.0.0.1 fixed it for me.
Did you try it?

[splittheatom]

I switched back to 127.0.0.1 and it still doesn't work.
Also, pushing the assets to disk works, but not the other two options: (To Project, To Disk then Project).
Is there a way to get an error log ? Maybe this can help.

[muziemo]

Have you solved it? I also encountered this problem. It was working fine before but suddenly it stopped working. I urgently need help.

[kiselev-dev]

I have had the same error for ~2 years. Currently using freshly installed Win11 Pro, Blender 4.0.1, and UE5.3.2, and still not working for me. It is 100% on the blender side since the MS store version and the one you installed from the installer behave differently. It could be related to the %USERPROFILE% containing spaces.

[RWOverdijk]

It could be related to the %USERPROFILE% containing spaces.

I doubt it, since this issue specifies MacOS. Even there I don't have a space in my username.

Also OP said that saving to disk works. What you're describing would be a FS issue.

[ReneBulla]

just had the same problem on windows 10 but i got it fixed on my side.
in blender "pipeline->utilitys->Start RPC Servers" gave me some kind of permission issue

i had recently installed a different python version and added it to my PATH so i figured maybe blender tries to use the wrong python version or something.

• I removed the python stuff from my PATH
• deinstalled python
• restarted the system
  and now it works again.

unreal 5.3.2
blender 4.0.2
send2ue 2.4.3 (with the community fix for blender 4.0)

[tanis2000]

@ReneBulla what version of Python are you using now? I suspect I am having a similar issue as the behavior is exactly the same on my M2 Mac. Running the "Start RPC Server" command shows an error. I need to figure out how to see the actual log of the python script execution though. Any pointers?

[tanis2000]

BTW why is the default port used to connect to UE 6776 when the actual server is listening on 6766?

https://github.com/EpicGames/BlenderTools/blob/4456efd7d57cc638944307cfe7efeb7401ee044c/send2ue/dependencies/remote_execution.py#L28

That might be the actual issue.

[tanis2000]

Ok my bad, 6776 seems to be the port the client is opening (TCP)... and I have no idea why. Anyway I tried to execute locally from a script the same commands that the extension is running when trying to start the RPC server and this is the actual error

Python: Traceback (most recent call last):
  File "/Users/tanis/Documents/Unreal Projects/CarToy/Art/pad.blend/Text", line 11, in <module>
  File "/Users/tanis/Library/Application Support/Blender/4.0/scripts/addons/send2ue/dependencies/rpc/base_server.py", line 266, in start
    self.start_server_thread()
  File "/Users/tanis/Library/Application Support/Blender/4.0/scripts/addons/send2ue/dependencies/rpc/unreal_server.py", line 34, in start_server_thread
    unreal.register_slate_post_tick_callback(base_server.execute_queued_calls)
AttributeError: module 'unreal' has no attribute 'register_slate_post_tick_callback'

Has something changed on the Unreal side of things?

[ashleydevelops]

Has anyone found a fix yet? I can't use Send2UE with macOS anymore.

I have tried all the fixes listed in the comments here. Nothing works.

[splittheatom]

Hello, I have just tried again and still no luck..
Unreal 5.3.1
Blender 3.6.5

[MischaAbakumova]

Ok my bad, 6776 seems to be the port the client is opening (TCP)... and I have no idea why. Anyway I tried to execute locally from a script the same commands that the extension is running when trying to start the RPC server and this is the actual error

Python: Traceback (most recent call last):
  File "/Users/tanis/Documents/Unreal Projects/CarToy/Art/pad.blend/Text", line 11, in <module>
  File "/Users/tanis/Library/Application Support/Blender/4.0/scripts/addons/send2ue/dependencies/rpc/base_server.py", line 266, in start
    self.start_server_thread()
  File "/Users/tanis/Library/Application Support/Blender/4.0/scripts/addons/send2ue/dependencies/rpc/unreal_server.py", line 34, in start_server_thread
    unreal.register_slate_post_tick_callback(base_server.execute_queued_calls)
AttributeError: module 'unreal' has no attribute 'register_slate_post_tick_callback'

Has something changed on the Unreal side of things?

Hey Tanis200, the documentation mentions that the port 6766 should be the port for UE communication. Anyone else found a solution?
https://epicgames.github.io/BlenderTools/send2ue/trouble-shooting/errors.html

[BohanLeng]

I believe it's not about the settings, but the OS.
Same Unreal 5.3.2 project opened, same Blender 4.0 file, exact same settings for both (went through send2ue Quickstart). And on clicking Push Assets:

• On Mac, "Could not find an open Unreal Editor instance!".
• On Windows, it works just fine.

[ashleydevelops]

Yes, it's about the OS. Windows works perfectly.
I tried the same file, same settings, same versions in both Windows and Mac.
(Using Blender 3.6.8 LTS and Unreal Engine 5.3.2 with the latest Send2UE 2.4.3 version).

It hasn't worked for 3 months on Mac. I can't work in MacOS anymore with my common workflow.

[BoomRaccoon]

I don't know if anything of that had to do with it but I write down what happened to me on windows today:

• tried pushing an asset to unreal after a long time not using blender
• gave me the same error
• looked at the python code in blender and it says it's looking for either the environment variable 'UNREAL_PORT' and uses 9998 if it's not found
• tried setting that to different values first and still got that error
• set it to 9998 afterwards and it started working for some reason (could also be because of multiple restarts)

I have no clue why it started working after that again because I set most settings back to the defaults and it keeps working but try looking up the the environment variable of unreal editor and setting it (even if it's the default 9998 (6766 is the one it will use after it found the editor instance)) 🤷‍♂️

Good luck guys

[ReneBulla]

So i again had that problem today on Windows

i just put the values from inside the file mentioned by tanis2000

BTW why is the default port used to connect to UE 6776 when the actual server is listening on 6766?

https://github.com/EpicGames/BlenderTools/blob/4456efd7d57cc638944307cfe7efeb7401ee044c/send2ue/dependencies/remote_execution.py#L28

That might be the actual issue.

inside the unreal settings

the Multicast Bind Address inside unreal was set to 0.0.0.0 on my end but last time it worked with this value.

so now for me it works again... im on windows but hopefully it might still help someone

[splittheatom]

Hi Rene,
Thanks for the information, tried on macOS but still doesn't work - I think this is OS related.
Is there anyone from the Send2Unreal devs that could support ? The issue was opened last November and the Blender to Unreal workflow is quite tedious...

[Anqui3tas]

issue still occurring.

blender: Version 3.6.9 (3.6.9 2024-02-20)
UE: Version: 5.4.1-33305029+++UE5+Release-5.4
Platform: macOS 14.5 (arm64)