ID 137860 - ZDefocus and Kronos error with "Directory was not successfully created" if the user account has a non-ascii character in the name

Problem summary
If you have a user account with an umlaut (e.g. Ü) in the name, trying to use a ZDefocus or Kronos node doesn't give any output and ""Directory was not successfully created" is given as the error.

This happens with Nuke 8.0v1 and above on Windows, with both the ZDefocus and Kronos node. It doesn't matter whether the GPU is enabled or whether the you're running NukeX or Nuke. The GPU accelerated ZDefocus and Kronos nodes in Nuke 7.0v10 do not produce these errors in the same user account.

Customer reported version
nuke.11.0v2

Customer reported platform
centos6

Steps to reproduce

1) Create a new standard user account with an umlaut in the name, e.g. ?llrich. You can make the ? by typing Alt + 0220.

2) Switch to the new user account and launch Nuke 8.0v1 or later versions

3) Create a Checkerboard, connect it to a ZDefocus node and then connect it to the viewer. Nuke will produce the "Directory was not successfully created" error.

4) Create another new user account with an umlout-less name and repeat the steps, the ZDefocus node will work.

Workaround
Change the name of the user and remove the umlaut.

Reproduced by support

Expected behaviour
Kronos and Zdefocus should work with an umlaut in the username

Actual behaviour
Kronos and Zdefocus did not work with an umlaut in the username