Unknown file store handler

Hi all,

I'm using a chunk loop containing a wrapped metanode that again contains a chunk loop (because of the need to convert the current row to a variable for input in Global Thresholder node of KNIME Image Processing). When running that workflow, I'm getting multiple errors:

ERROR Loop End    2:84  Unknown file store handler to UUID e63fdfa8-96e9-4ddc-9d49-aa4f2b3504f3

Is this a bug? How can I work around this?

Best,

Jan