Trial version not working correctly

I just installed a trial version of DEVONthink Pro Office 2.3. However, I cannot access the preferences and I can also not import via Image Capture. Both menu items, “Preferences” and “Capture…” are greyed out (along with many other menu items). My scanner is a Canon Canoscan Lide 210 and it works perfectly well with Image Capture. What is wrong here and what can I do to make it working?

… after a restart all menu items seem to be working.