Please post code snippet of your application and how you have built the same.
you can check the attached file
void Start() works when the app first run
other code you just have a quick look.
When I fist run, everything works fine, but the second time or third time, there is an error as I mentioned.
USB30_Interface.cs.zip 2.4 K
It seems that the similar issue is addressed in the following post. Could you please refer it and update if the solution works for you or not.
Thanks & Regards