designer errors

I have seen these before but not sure how to fix it. When we had a PS support person locally he would toggle something to fix it and then the error would go away - the errors I am getting are these:

“Target Value Binding” expression must resolve to either a PrincipalModelList, String, IURI[] or String[]

“Target Value Binding” expression must resolve to either a String, IURI or IPrincipalProvider

I think he used to copy these out of their location and just paste it back and it would go away but it isn’t working for me - does anyone else know how to get around these ?

figured it out - refresh the bindings view and then cutting and pasting the target value bindings back in resolved it