Unable to Compile with HotReload in 4.16

If I have the editor running I am unable to compile the project from VS studio. There are no errors in the code and If I shut down the editor the project complies successfully and I can restart the editor without issue.



1>------ Build started: Project: CCam, Configuration: Development_Editor x64 ------
1>  Compiling game modules for hot reload
1>  Performing 2 actions (4 in parallel)
1>  [1/2] Link UE4Editor-CCam-8247.dll
1>  [2/2] Link UE4Editor-CCam-695.lib
1>     Creating library C:\UEProjects\CCam\Intermediate\Build\Win64\UE4Editor\Development\UE4Editor-CCam-8247.lib and object C:\UEProjects\CCam\Intermediate\Build\Win64\UE4Editor\Development\UE4Editor-CCam-8247.exp
1>     Creating library C:\UEProjects\CCam\Intermediate\Build\Win64\UE4Editor\Development\UE4Editor-CCam-8247.suppressed.lib and object C:\UEProjects\CCam\Intermediate\Build\Win64\UE4Editor\Development\UE4Editor-CCam-8247.suppressed.exp
1>ERROR : UBT error : Failed to produce item: C:\UEProjects\CCam\Intermediate\Build\Win64\UE4Editor\Development\UE4Editor-CCam-695.lib
1>  Total build time: 3.66 seconds (Local executor: 0.00 seconds)
1>C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V140\Microsoft.MakeFile.Targets(37,5): error MSB3075: The command ""C:\Program Files\Unreal Engine\UE_4.16\Engine\Build\BatchFiles\Build.bat" CCamEditor Win64 Development "C:\UEProjects\CCam\CCam.uproject" -waitmutex" exited with code 5. Please verify that you have sufficient rights to run this command.
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========


I did not have this issue in 4.15. Anyone know what is happening? I have tried the same with a new empty project with both the binary and source versions of the engine. Hotreloading simply does not work for me anymore :frowning:

How can I fix this?

Just wanted to add this problem goes away if I use the compile button from the editor itself.

I have the same issue :frowning: I have built a binary version from source, so I thought it was me messing up something in the process. Thanks for the workaround, I will be able try it in a few days.

@Waves the problem is the compile button isn’t showing.

This thread was about 4.16 and doubtful has anything to do with the current release.

In any case I gave up on hot reloading long ago. I still use it if I want to test a quick change in the file I’m currently working on. However I find that as your project grows and you start adding modules and moving code to plugins hot reloading becomes increasingly unreliable. As in it would compile and play fine but doesn’t include all the latest changes. So it can not be trusted to be accurate picture of your current dev status.