after installing f-droid, it always fails

I installed F-Droid from the f-droid.org homepage on a brand new S6.

I started f-droid. It ran, but after some time, it crashed. Android reported that it had crashed. There was no error from f-droid

I re-ran f-droid.

This time, it did not seem to crash, but only about 10 f-droid apps were listed.

I manually updated the repository.

It says, "There are no updates available"

I changed the update frequency to "hourly" and manually updated the repository nine times.

But still there are only 10 f-droid apps listed by f-droid.

I have used f-droid successfully on an S4, but this is the first time to use it on an S6. It is a disappointing experience.

Why is f-droid not working properly, and why is f-droid not showing any error messages when it fails like this?

Could somebody please explain what I need to do to get f-droid working on this S6?