Make sure the PBL files that contain the DataWindows used by a Web Forms application are copied to the directory specified by the PBLibDir
global property.

By default, the PBLibDir global property assigns C:~PL_ as
the directory for application PBL files. This corresponds to the FileCommonC~PL_ subdirectory
of the
applicationName_root directory
in the server�s virtual file system path.

On Vista and later, TreeView DataWindows are not visible if
you have not given the IIS_IUSRS group full permissions
(including write and delete) to application directories. See Application Directory Permissions
.

In AJAX-enabled Web Forms applications, DataWindows do not
appear if a column in the DataWindow uses a JavaScript keyword
for its name.