similar problem in Assertion failed: Assertion failed on expression: '!GetMainEditorWindow()' - Questions & Answers - Unity Discussions
but not the same,I’m using unity hub2.3,I re-logined,and make sure my license is updated，but the problem is still exists and I cann‘t open the project I’ve created，and while creating a new project the“Assertion failed on expression: ‘!GetMainEditorWindow()’ “ problem occured,and the editor is unusable.
Well,I’m using a 2018LTS version.Things are strange for the 2020a version on my computer works normally.
Does anyone know how to fix this problem?Your help would be appreciated!
Problem solved by reinstall the unity hub and updating to student license,hope it could help someone else.