Hi, i´ve the same problem with such i diagonal line.
Using Asiair (non pro) 1.5.3, Canon D550, Asi120 mini, EQ6.
What i can say is that the saved pictures are ok, only the display of the picture in "Live"-Screen is with this error. If i switch the bining in the preview, the error is gone.
I use a Andoid Tablet. With my Iphone there are no errors like this. (I`ve therefore reinstalled the app on my android tablet, but same error).
I mean, i can take photos and all functions are still working, except this.
Greetings from Germany
Marcel