CSV File "imagedata.csv" Not Found.
You might be trying to preview this page in RapidWeaver, but the CSV file to your gallery could not be located. This could simply be because the CSV file is on your web server, and RapidWeaver is unable to access it currently. You could try adding the CSV file as a resource in the RapidWeaver sidebar and then link to that instead. This will then let you test and view the gallery in RapidWeaver preview.
Alternatively if you are seeing this error on your live (published) webpage, then the relative path you have specified to the CSV file is incorrect or the CSV file is not presented in a format that ProGallery understands. Please refer back to your documentation for complete setup instructions and examples of CSV files.