Here's what I would do:
I would suggest clearing the themes cache on the Theme Selector page.
You might even try Purge all caches from Site administration > Development
You could try switching to another theme, clearning /purging the caches, and then going back to Fordson and doing it again.
The Fordson documentation specifically says it's best to perform the updates under a different theme, by the way.
If all this fails, turn on debugging, and see if it throws relevant errors.
In addition to what has been already mentioned, I suggest opening "Activities/Resources" in Fordson and seeing if "Show only custom menu" is enabled. If the custom menu is enabled and empty, you will probably not see any activities and resources. Here is a screenshot of an older version of Fordson.
I'm guessing you changed up the settings on the Fordson page for activity chooser. Please uncheck the box as Hartmut suggests. That will fix your issue.
Alternatively, if you click the checkbox then only the modules/acitivities you type into the text box will appear.
This gives you the ability to control what tools a teacher can use. Maybe you only want 4 or 5 activities available for teachers.
This would allow you to do that but you have to know what and how to use that setting.