[IL2CPP][UWP] Strange Error: "IOException: Win32 IO returned 234"

Questions & Answers
1

We met a strange problem, please help us~~
We want to publish our project to UWP platform by IL2CPP. It works fine on some of our computer, but on others, it throws a strange exception, as follow:

131849-build-exception.png
131849-build-exception.png1272×118 25 KB

Unity version: 2018.3.0~2018.3.1
VS version: 15.9.5
Api Compatibility Level: .Net standard 2.0

This problem will appear even we try a Empty project on some computer, and it will never appear on other computer. We can’t find the different between these computers, they have same version of Unity/VS/Windows.

And, if we change the target SDK to lower (i.c. 14393), it will work. but, we must use target higher than 16299, so we can’t fix it by this way.

Could anybody help us to fix this problem? Thanks a lot~~~

2

Same Error.
Unity Version 2018.3.2f1
Target: UWP
Scripting backend IL2CPP (.Net back end will build the unity report .net backend is deprecated)
Looks like part of the SDK file cannot be copied.

3

We update Unity to 2018.3.3, and it works! I think this issue has been fixed in 2018.3.3

4

i meet it too, Win32 IO returned 234. Path:
when this error is happened i use File.Delete to delete a file,
that file is named too long, and file size is zero,
i saw other people meet it and solved this problem, that is Shorten file path
so i think some string in the API cannot to long
Unity 2018.2.21,

otherwise, i use Unity2018.2.6 is fine,
Weird

5

Finally, we found the solution of this issue.
The reason of this error is, the full path of the file in Windows SDK is too too too long… The length of the path in default install folder is 231 characters. System.IO.File.Copy can’t handle this.

To fix it, you can install windows SDK in a shorter folder, like "C:\Z", to reduce the length of file path. but, unfortunately, you can’t change this install path when you have installed any windows SDK. so, you must do as follow:

  1. Uninstall Visual Studio and all windows SDK.
  2. Install windows SDK FIRST, and you can select a short root path. ( Important! if you install VS first, it will install a set of windows SDK to default folder and you can’t change it!)
  3. Install Visual Studio

And then, you can publish UWP project again! Hooooooray~~~

6

Maybe you can try to delete this file
“C:\Program Files (x86)\Windows Kits\10\References\10.0.18362.0\Windows.ApplicationModel.CommunicationBlocking.CommunicationBlockingContract
2.0.0.0\Windows.ApplicationModel.CommunicationBlocking.CommunicationBlockingContract.winmd”
And try to build again