More and more DataSpec errors

I've been seeing more and more of the following error:

"DataSpec generated by configure does not match spec after execution."

This is usually accompanied by some very strange behavior, such as columns from one branch of a workflow popping up in entirely separate branches!

The error seems to occur mostly when I've used a Java snippet node, which I've then copied elsewhere in the workflow rather than rebuild from scratch. When I open them up they appear to be configured properly (no columns appearing that shouldn't). 

In some cases the error only becomes apparent further along the workflow. For instance, I sometimes see it after a Join or filter node, or at the end of a loop. 

Editing them and rerunning the Java snippets or effected official nodes doesn't seem to help; I have to delete the snippets and insert blank ones. This is obviously a pain, since copying and editing a node is much more convenient than setting up a brand new node that's adding several columns and contains a substantial block of code. 

Any ideas what's causing this?

 

Have you seen this thread yet? Are you still on KNIME 2.8.0, or this also happens with workflows created with 2.8.1?

Ah, no I hadn't and I'm still on 2.8.0. I'll upgrade now.

Thanks.