Lack of internal memory
Especially when you start using library items, high demands are put on your computer’s internal memory. If it has been a while since you last shut down your computer (not in standby or hibernate modus), please shut it down completely and restart it.
If this doesn’t help, your computer might be outdated.
My advice is to place the items only after drawing the building itself.
Your web browser causes a slow connection
You can check this by installing another web browser, such as Internet Explorer, Safari, Firefox, or Chrome, and using it instead.
If you notice that certain functions don’t work in Floorplanner, it might help to use another web browser temporarily.
I recommend using Safari for Mac/Apple computers. In case of (temporary) problems, switch to another browser.
I recommend Chrome for Windows/Android computers. Switch to another browser if there are problems.
The internet connection itself is slow
If you use a wireless internet connection, try connecting the computer straight to the internet modem/router using a network cable.