Sorry for the delay in response.
The form needs to be reader extended through LiveCycle RE for paper form Barcodes to work in Adobe reader.
The Reader Extensions function in Acrobat Professional does not include enabling an interactive PDF form for the PaperFormsBarcode object.
The barcode turns grey in Reader because the form does not have the barcode right. On the other hand, any version of Acrobat provides barcode encoding. If you want to distribute a barcoded form for Reader clients, you must use LiveCycle Reader Extensions to apply a barcode right.
Reference article for more details: Adobe LiveCycle ES4 * Design tips for using a paper forms barcode
Let us know if that helps.
Alright. Please tell us how can we use LiveCycle Reader Extensions. Also please share the download link. Thanks.
Buy "LiveCycle Reader Extensions", install it, read the documentation, and use the software.