This typically happens when you try to select a CSV file in POLYDATA by browsing to some other location (other than the Inputs folder) where CSV file is located. In order to circumvent this, -While running simulations in Workbench, before opening POLYDATA, import the CSV file by right clicking on “Setup” cell, select “Import any file”, browse to the folder where CSV file is located and select it. -While running in POLYMAN, before opening POLYDATA, import the CSV file by going to “File > Import > CSV file”, browse to the folder where CSV file is located and select it. Thus once the CSV file is imported, it gets copied into the corresponding Inputs folder. Then in POLYDATA while trying to select CSV file, you can simply go to Inputs folder and select the CSV file.