Same thing happened to me last night. I've inserted the Browser object right after updating to R50, then it won't let me save my project. I get an error saying "Array is expected". Tried removing the Browser object, but Construct 3 crashes all the time. Tried opening the project using the different older versions of C3, but it won't let me and I get the error saying that "!Qry is not a function". I'm pulling my hair out of frustration.
Smh, the life of a beta tester.