Could not create reactwidgetwrapper

I have just upgraded from 7.6.0 to 7.20.1.  All worked well locally but am getting 'could not create widget' messages when deployed to our on premise linux servers. Could not create widget mxui.widget.ReactWidgetWrapper Could not create widget mxui.widget.NavigationTree I get the reactwidgetwrapper message on my loginpage. I've stripped out scrollbar, menu bar and downloading the loginform widget again from the app store. Any suggestions?
1 answers

I've seen this same error in the UI whenever an user doesn't have read/write rights on the attribute that a widget is used for. In these cases it does apply on the standard Mx input widgets however, but it might be worthwile to check the access rights though.