I’m getting inaccessible labels, but the simulation seems to be running fine

i've started a new simevents model using the example burst entity generator. The simulation works, but all the signal labels show inaccessible, but the scope graphs are fine. i've just installed 2020a, and the same happens on an old model i just imported (where the labels used to work)

[Abdolkarim Mohammadi]

Did you find out what was causing the problem?