Converting from 4.15.3 to 4.18 "is inaccessible due to its protection level"

Hi there

I’m trying to convert a Project from Version 4.15.3 to 4.18. Here’s the Error Code:

Project files could not be generated. Log output:

Running C:/Program Files/Epic Games/UE_4.18/Engine/Binaries/DotNET/UnrealBuildTool.exe  -projectfiles -project="D:/SL Projectfiles/UE4/SeaHouse 4.18/SeaHouse.uproject" -game -rocket -progress
Discovering modules, targets and source code for project...

While compiling D:\SL Projectfiles\UE4\SeaHouse 4.18\Intermediate\Build\BuildRules\SeaHouseModuleRules.dll:
ERROR: d:\SL Projectfiles\UE4\SeaHouse 4.18\Source\SeaHouse.Target.cs(19,12) : error CS0122: 'UnrealBuildTool.UEBuildBinaryConfiguration' is inaccessible due to its protection level
ERROR: d:\SL Projectfiles\UE4\SeaHouse 4.18\Source\SeaHouse.Target.cs(17,23) : error CS0051: Inconsistent accessibility: parameter type 'ref System.Collections.Generic.List<UnrealBuildTool.UEBuildBinaryConfiguration>' is less accessible than method 'SeaHouseTarget.SetupBinaries(UnrealBuildTool.TargetInfo, ref System.Collections.Generic.List<UnrealBuildTool.UEBuildBinaryConfiguration>, ref System.Collections.Generic.List<string>)'
ERROR: d:\SL Projectfiles\UE4\SeaHouse 4.18\Source\SeaHouseEditor.Target.cs(19,12) : error CS0122: 'UnrealBuildTool.UEBuildBinaryConfiguration' is inaccessible due to its protection level
ERROR: d:\SL Projectfiles\UE4\SeaHouse 4.18\Source\SeaHouseEditor.Target.cs(17,23) : error CS0051: Inconsistent accessibility: parameter type 'ref System.Collections.Generic.List<UnrealBuildTool.UEBuildBinaryConfiguration>' is less accessible than method 'SeaHouseEditorTarget.SetupBinaries(UnrealBuildTool.TargetInfo, ref System.Collections.Generic.List<UnrealBuildTool.UEBuildBinaryConfiguration>, ref System.Collections.Generic.List<string>)'
ERROR: UnrealBuildTool Exception: Unable to compile source files.

I’ve tried a couple of things (converting from 4.17 to 4.18, disabling AntiVirus…) but nothing seems to be working.
It says “is inaccessible due to its protection level”, but check out the screenshots.

Idk but it looks like these are set to public, and I guess I wouldn’t be able to change it anyways, cause it’s getting created in the converting process.

It completes to 100% and then the error message appears. So the files are actually created, when I try to open the project I get the “The following modules are missing or built with a different engine version: blabla.dll Would you like to rebuild them now?” When I hit yes it says “Try to rebuild from source manually”

Any help would be greatly appreciated :slight_smile:

I just tried to convert some other project and it worked. So I guess there’s something wrong with my project.

Wasn’t able to fix this problem, I just migrated the level including all the content to a new 4.18 project file.

Take a look at this post. The solution seems to be working.

https://answers.unrealengine.com/questions/718575/error-when-updating-to-418-generating-visual-studi.html