Live Coding cannot be enabled after hot-reload has been used

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1

Hi,

after project upgrade from 4.20 to 4.22 I was looking forward to try live coding feature, but so far I was unable to make it work.

When I launch editor ( without debugger ) and enable experimental live coding feature, then after I pressed Compile in editor I got this message:

Live Coding cannot be enabled after hot-reload has been used. Please restart the editor.

I restarted editor several times, but so far nothing changed, do I need delete some hot reload cache?

Any help is appreciated.

Thank you,
Jakub.

1 Like
2

Same issue here.

3

Try closing the editor and deleting the UE4Editor-MyGame-####.pdb and .dll files in Bin/Win64. When you start the project again, it will want to recompile. After it has done so, it should be possible to start a Live Coding session.

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4

I deleted all from \MyProject\Binaries\Win64, pop up window with message about missing modules jump up.
I confirmed rebuild of those modules. Editor window appeared, but still with same message about hot-reload beeing used.

5

I could reliably replicate the issue by simply hitting compile within the editor, so I guess just avoid doing that.

For me, the solution was the following:

  1. Open the UE4 editor via the .uproject as well as the .sln file
  2. Disable the Live Coding feature (under the dropdown next to ‘Compile’)
  3. Close the UE4 editor
  4. Build the solution (ctrl + shift + B by default for VS2017 at least)
  5. Open UE4 editor again through the .uproject

I doubt it matters, but I’m using Development Editor for the solution configuration.

Hope that fixes it for you too.

5 Likes
6

Thank you very much!

7

Now I know I am interjecting here, but why do you launch the editor threw the uproject instead of running it threw the compiler (visual studio)?

8

I tend to always load projects through the .uproject file because I don’t like waiting for the editor to load each time - old habits die hard I guess :slight_smile: If things aren’t working as I expect, I will fall back to launching the project through the compiler (F5).

With that being said, if the steps work through using F5 rather than opening through the .uproject then that’s great, but I haven’t had to test it like that just yet.

9

when you need to rebuild your project, instead of relaunching it with f5, right click the game project and choose build, you should get a notification that the build was successful from the uproject, although this can sometimes desync and a restart of the uproject is required. This is what I do at least

10

First time I tried this, it doesn’t work so I was looking for another solution. And in the end I think what saved me was:

( Similar to what you have suggested )

  1. Enable live coding in editor ( for me it was in attached editor)
  2. Recompile with this new setting
  3. Start editor again.

Now I’m facing some errors in live coding console, but that’s probably for another task :frowning:

Error I’m facing when I try recompile via live coding is:

Error 0xEA while reading from pipe. Size: 260, read: 260
11

Did not work for me. Still the same error when I “Start Session”

12

For all of you to whom deleting intermediate/binaries and/or re-compile the entire solution didn’t work: you might have the same misleading error as me.

Context: I upgraded the engine (source c++ version) from 4.22.1 to 4.22.2 and Live++ stopped working. Didn’t matter the configuration used for compiling the engine, all tested ones failed (DebugGame Editor, Development Editor). CTRL+ALT+F11 didn’t open any console window. When using the option next to the compile button in Editor (Start Session), I got this error

280197-unknown.png

I never use hot reload. It’s a big no no for me, so I didn’t believe that error. Also, I cleaned and re-compiled the entire solution before, so no hot reload binaries anywhere. I checked the logs and I found this line:

LogLiveCoding: Error: Unable to start live coding session. Missing executable 'P:/Perforce/Engine/UE-MyProject/Engine/Binaries/Win64/LiveCodingConsole.exe'. Use the LiveCoding.ConsolePath console variable to modify.

Turns out that, during the upgrade (and, if not, during the solution re-build), the LiveCodingConsole.exe was removed. All I had to do was to re-compile that program and everything was back to normal again.

I have the feeling that, that window, is a default error. A misleading one.

Extra tip: if you are one of those that adds c++ classes from within the editor, disable Automatically Compile Newly added C++ Classes in the Editor Preferences or you will have this problem for real.

280198-unknown-1.png
280198-unknown-1.png728×210 5.49 KB

Cheers and good luck!

7 Likes
13

thanks, deleting .dll files worked<3

14

Super helpful! Thx!

15

Didn’t work for me. still the same problem

16

Hi. Anonymous user said: “Turns out that, during the upgrade (and, if not, during the solution re-build), the LiveCodingConsole.exe was removed. All I had to do was to re-compile that program and everything was back to normal again.”

Does someone know how to do just that, recompile LiveCodingConsole.exe?
I’m using a compiled UE version, building it from scratch doesn’t seem to reify that exe unfortunately :frowning:

17

Assuming you run a raw source build run this command in cmd

EngineFolderName\Engine\Binaries\DotNET\UnrealBuildTool\UnrealBuildTool.exe LiveCodingConsole Win64 Development

it will compile the LiveCodingConsole

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