I very much appreciate your feedback on this application as I am unable to test all configurations and have not seen this issue during testing.
I assume that you are using Version 1.2 and Windows 7; please let me know if otherwise.
Prior to version 1.1, if there were no records to export withing the date range specified, you would indeed get no response, just a page reload.
Under Version 1.2, when you click on export, the page should reload and either display a message near the export button that warns "no records to export" or else, yes, it is supposed to export a CSV file. Depending on your browser configuration, you may be asked if you want to save the file in your default download folder, save it elsewhere potentially under another name, or open the file using using a default program (such as Microsoft eXcel) or a different program (such as Notepad or Wordpad (Under Windows).
With respect to flashing some other fields and then removing them, that would be expected if the "Require Login" option was checked. In that case, several fields concerning "Courtesy Username" validation would become hidden.
Your verification that a record exists in the table is helpful. My question is whether that record's acknowledgement date falls withing the date range specified on the settings before you press EXPORT. Certainly, if you set the dates to 2013-12-01 and 2014-02-01, any records in the table would fall within that range (as it would fall between the release of he RnU plugin and the date of your reported trouble.)
Can you verify the date of the record in the table and the date range specified for the export? Have you tried a different browser? If so, have you seen the same result? If not, please consider trying that.
What effect does the PURGE button have for you? It should find exactly the same number of records as using the export button as both rely on the same date range. Fell free to press PURGE once, as if any records are found, you should have an opportunity to confirm using the CONFIRM button that replaces the PURGE button. You may abort the CONFIRMATION by leaving the page (e.g, go to the DASHBOARD or by changing the dates.) I would be interested to learn if the EXPORT button did nothing, but the
If you are interested, there is a test plan in the /test folder of the plugin. Feel free to give it a go and let me know where it fails for you (as well as the OS and Browser that you are using.) Running the plan would take between 15 and 30 minutes, and I understand if you don't care to do so.
I look forward to hearing from you.