Hi Mike, you can update your Add Invoice formula to set the nextURL parameter to ensure that, every time a user clicks the button, they will always be redirected to the parent project:
URLRoot() & "db/" & [_DBID_PROJECTS] & "?act=API_GenAddRecordForm&_fid_48=" & [Record ID#] & "&nextURL=" & URLEncode(URLRoot() & "db/" & Dbid() & "?a=dr&rid=" & [Record ID#])
One thing to note with this formula is, even if users click the button while on a Projects report, after adding the related invoice they'll be redirected to the form for the parent project record.
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Brian Cafferelli
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