[SOLVED]Problems simplelist after update EL to JEM and Joomla

I didn't find rebuild, can you please tell me in which location it is..

go to admin>components>JEM>categories>Rebuild
In JEM categories theres in top right "Rebuild"

Thank you! I have rebuilt, but still the page is empty.

Yes, but still rebuild option didn't solve my problem.
Is there any other way to solve my problem

Hi, how did you proceed updating:
I think on Joomla! 2.5.27 you should first upgrade from EVENTLIST to JEM. EL and JEM are compatible for Joomla 2.5. And after you can update to Joomla 3.7.+
I think I found some notices here in the forum who are talking about problems.
EDIT:
Look e.g. for
Upgrading from EventList 1.0.2 Stable in JEM 2 years 5 months ago #16480

Hi,
Thank you for your help!
Issue is resolved.