Hi @Vikram Dabas
happened on a 2017 Macbook Pro, most recent OS, with a noname 1g stick. It was from the welcome screen and the app dissapeared/crashed quietly. Nevertheless your response made me use a different approach choosing "new user" from the welcome screen and configure the sync from settings after the app started. That worked perfect with my WebDAV, so for my purpose the problem is at least "worked around" (better to say solved since I will not go through the welcome sequence any further). Unfortunately I cannot set up a Test account on the Cloud, sorry.
Thanks for caring, I wish you good luck finding the bug in the welcome sequence!