Repetitive switch camera over 100 time get crash

My project will often open and close the camera many times。many times later (more than 100 times like 128 and 103),when “nuitrack.Nuitrack.Init();”, it will crash,and I got not any error debug in unity.

OS : Windows10
Editor : Visual studio and Unity 2019
Language : C#
Device : Intel Realsense 415
Nuitrack version : 0.28.0
RealSense SDK : v2.21.0

It looks like you have no license file for your device or Nuitrack can’t find it.
Do not set up the nuitrack.config file through nuitrack.Nuitrack.Init();.
Do it by setting up the NUITRACK_HOME environment variable.
If you have to use the custom config file, change the “LicenseFile” value inside the file.

Is that have other function start nuitrack?
Can you show me some example please?
Thanks for your reply