Hi subhashnautiyal50, Thank you for contacting support. I understand that you are unable to open downloaded pdf files. Please update Firefox 22 to version 26. In this version the download pdfs are saved in mnt/sdcard/Download/ You can set the permissions to which app on android has access to that folder. Therefore, your pdf reader will have to be able to open that folder. The alternative is to obtain a file manager application for your android to move the download to where the pdf can be read by the desired application or reader.