Hi Mario,
I have recorded all my scenarios in 11.51 and there is version compatibility issue in Vugen and LG for Ajax TruClient Protocol, so as of now I can't move to 11.52.
As you can see in attached screenshot, we are removing one custom group which was created in previous step. Once we clicked on cross button to remove it, this prompt is coming. So it's not closing main browser or another browser infact it's in current browser only.
Please let me know if you want more details.
Regards,
Deepak