I did some investigation on this and it looks like it is an empty file that is generated sometimes in Unity Playmode. I wouldn't worry about it.
However, I would like to mention that Unity 2017.1 is not a supported version of Vuforia 6.2.10 and it is recommended you use Unity 5.6 instead. You may run into other unknown issues while using 2017.1.
I did some investigation on this and it looks like it is an empty file that is generated sometimes in Unity Playmode. I wouldn't worry about it.
However, I would like to mention that Unity 2017.1 is not a supported version of Vuforia 6.2.10 and it is recommended you use Unity 5.6 instead. You may run into other unknown issues while using 2017.1.
Thanks,
-Vuforia Support