Hello,
when I drag a component from the component-panel to the div-panel (I dont know the name of this…) very often the second screen (with the element properties etc.) which is on my second monitor freezes and you can only see the screenshot-picture of the component covering 50% of the window. All menues are gone, only the picture is there, the rest is gray.
Then the only possibility is to restart PG.
This happenes in Vers. 5.7 and 5.8.