"Fatal error: Unknown"

We are using Omeka 1.5.3 with Scripto. All has been going well except now new items are not updating when an image is transcribed and also not re-ordering from least to most completed. Old items added previously continue to update and re-order though!

We have noticed with these new items that for some reason the Dublin Core Audience field is blank whereas in the others it has a self-generated number. Not sure if that's relevant.

When we try to manually edit any of the Scrito fields back of house, such as percent needing review, we get this error:

Fatal error: Unknown: Cannot use output buffering in output buffering display handlers in Unknown on line 0

We'd greatly appreciate any help anyone can provide.

With thanks,