Sync Preview Issue

I’ve got an issue that has popped up in the Sync program. I’m running version I’ve got several Sync projects. I’m having an issue with one of them, using the Preview option. If I call up one of the data items, and use the Preview button, I receive an error: “SelectCommand.Connection property has not been initialized”. (See attached screenshot for full message, but this is the important bit.) This happens with every data item in this particular project. I can call up a different project, and preview. The one that’s giving me issues, however, will successfully sync. It only errors when I try to use the Preview option. Anyone seen this before?