Xibo Player not showing media, frequent error messages

Hi! I have an installation of Xibo 1.7.8 with a layout consisting of a background image and several embedded webpages that show different things (java applet, a few embedded widgets, etc). The player only loads the background image, and won’t show any of the webpages. I am getting frequent error messages in the log that look like this:

MainForm - ChangeToNextLayout. Prepare Layout Failed. Exception raised was: Specified argument was out of the range of valid values.
Parameter name: Unable to set and start a media node.

I did some searching on Google and these forums, and the most frequent suggestion is to make sure I have a fully qualified path to the CMS library in the settings. I have done that (in this case /grp7/xibo2/www/xibo-cms/library/) and I’ve verified that that path in the library settings puts new library items in the correct folder, so I am pretty sure I have that part right.

Is there anything else I can try to get this resolved? I’ve also tried verifying all modules and it didn’t seem to help either.

Thank you!

OP replied in a PM saying the problem was resolved