It’s hard to say what may be your problem.
One possible problem: Have you installed the latest java version? There were some changes to my.openhab some time ago and with an older java version my.openhab stayed offline (and AFAIK hasn’t created those two files). But you know where to look for these files?
You can find many informations about the java update (how to check which version you have and how to perform the update) in this thread:
First, you have to make sure that my.openhab.org shows ONLINE when you use it. If that’s the case, the App will work virtually straight away.