If I use more than one slide in the Nivo slideshow and have that activated in universal slider area on one of my multi-sites, this is what displays: http://www.c2cinsites.com/nivoslider-test2/
-> Are you not seeing images pop up all in the top corners of that webpage?
If I add another nivo slideshow as a shortcode in the body content, that shortcode works and now the universal slider works also – I have that configuration set up here: http://www.c2cinsites.com/nivoslidetest/
I am not seeing any error messages, everything is up to date, Nivo slideshow works fine on other multi-site sites if a shortcode is used, the issue appears to be how the universal slider is set up.
Let me know if you need more information. Thx!