5.5 OSC Plugin not working when using localhost / 127.0.0.1

General Issues and Bug Reporting
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Summary

In the new engine version 5.5 the OSC Plugin is not working if you are using the local host address (127.0.0.1) as the address for both Server and Client. This could be a me issue but seems that some more people struggled with it.

Instead if you are using your IPV4 address it works as intended. This is an issue that I only had in the UE_5.5 update as previous versions did not have a problem using the 127.0.0.1 as the address.

Please select what you are reporting on:

Creative

What Type of Bug are you experiencing?

Other

Steps to Reproduce

Enable OSC Plugin and create a server. From my tests if you set the address as 127.0.0.1 it doesn’t bind to messages send to that address.

Expected Result

Having the OSC Server / Client work with 127.0.0.1 as the address.

Observed Result

Server not binding to received messages when using 127.0.0.1 as the address.

Platform(s)

Windows 11 x64

2

Hey got the same problem here! Hope someone got any solution

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I don’t get the second print at all (the “Hello”)

2 Likes
3

I just upgraded from 5.3 and having the same problem. The OSC Server is created but my “On Osc Message Received” is not called.

1 Like
4

Oddly, I got it working. I had to enter in “0.0.0.0” for the receiving IPAddress in Unreal Blueprints. Even though my sending app is sending to 127.0.0.1. Not sure if it’s a bug or something I just don’t understand.

8 Likes
5

confirming this is happening still on 5.5.1, but as above, using “0.0.0.0” for the server ip works fine for a client sending to “127.0.0.1”

6

Hi, Same thing here, switching server IP from 127.0.0.1 to 0.0.0.0 is receiving local messages

1 Like
7

You guys are amazing! I can confirm that both the issue and the fix hold true not just when using the OSC Plugin, but also when using the OSC Protocol plugin for Remote control. This was driving me absolutely bonkers for not even being able to receive simple OSC messages on localhost. In the case of Remote Control OSC, using “0.0.0.0” in the relevant section of the project settings fixed it. Hopefully this will be sorted in UE 5.5.2

1 Like
8

Hi,

I’m using Remote Control, but it only works if the RC window is open. If I start Unreal, open the project, and press play, the web interface doesn’t trigger any changes, and Unreal doesn’t respond to them. Is this expected behavior?

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9

I think I found it, yes you need to have this window open , I just noticed with this window closed the RCP icon dissapears and it comes back up with the window open.

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10

lovely, thx :slight_smile:

11

Thank you, I had the same issue not receiving OSC messages with local IP address while this used to work before. Setting it to 0.0.0.0 also fixed it for me.

13

Also confirming 0.0.0.0 works. Thanks for finding that fix!

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To be able to send messages to the OSC server on a remote machine, you must also create an inbound rule for the port used by the OSC on the UDP protocol in the firewall to authorize communication.

15

This is why you lose many hours with unreal sometimes before you find this workarounds :confused: Thanks for sharing!

16

UE5.5 here, also reporting it works with 0.0.0.0 config

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I am also confirming that this solution is still the correct answer.

I must say, as a long time Unreal user (something like 9 years) this is the kind of thing that really just drives me bonkers. I wasted a whole hour today troubleshooting a project that used to work on 5.3, only to realize it was something I couldn’t possibly debug without a weird magical trick.

Not a lot to really do about it, but that kind of thing just really grinds my gears with Unreal.

18

FORT-892573 changed to ‘Needs More Info’. We’re missing information that would help us determine the source of the issue.