Notice: Undefined index: settings in panels_renderer_standard->render_pane() line 495 panels_renderer_standard.class.php). this is the original error. this is my contribution to the issue on drupal.org
Hey, I was able to resolve this error pretty easily. I had been working with some new styles, making a clone of an existing, changing styles around on a specific panel pane. then, i decided that i really needed to make the change to the entire column. so i added a style there and changed the panel pane style back to the original style. i then began receiving the error.
I was quite sure what was going on after reading this post (and thanks @merlinofchaos! for everything!). I recreated the offending, or broken panel pane to make sure it worked properly, deleted the original pane and saved the page. the error is now gone.
then, i added the original style to the new, recreated pane. now, all is correct and the error is gone. and i have the new style on the column so that i can style the whole thing the way that works best for me.
so there never was actually an empty style, i believe that the system just got a little confused with the multiple changes. that also seems to be consistent with some drupal panel behavior. sometimes you just need to delete and recreate rather than fix unless you want to really dig into the db. and i really don’t!
small price to pay for the amazing panels module. @merlinofchaos – you rock.