Problems reading data packets from the ouster

[Vincent Perrier]

Hey, I'm building a program using your lib that read the data packet stream from the ouster and converts it to pcd files.
I was wondering what could cause this error:

I do set the Lidar mode a bit earlier in the code:

and the error gets thrown in this part that was inspired from your project's tests folder:

I think it might be because I am using the Ouster os2 but then again I am setting it into a well supported mode.
Any pointers would be great,
cheers !