The file extension XDP marks so-called XML Data Packages of the Adobe Acrobat document software. Xdp files are an XML container that contains the content of a PDF document along with forms (Adobe XML Forms Architecture (XFA)) and template data.
The XDP format makes it possible to convert a PDF to XML and back into a PDF without loss of information. Xdp files are mainly used by LiveCycle Suite.
Most often resolving problems with opening XDP files is very simple. Just install an appropriate program that supports such files. All of the listed programs support XDP files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of XDP files or offer file conversion options, but may not be capable of editing such files.
It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate XDP files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the Adobe Acrobat applications is not on the list, select "Browse" option in order to manually locate the directory where Adobe Acrobat has been installed.
Sometimes problems with opening XDP files may not lie with the application itself, but can arise due to other causes, such as: