Where does the package originates from (especially on what version was it created)?

Als if you configure log4net logging in EPiServer.log you should hopefully get a more detailed error including stacktrace.

I am importing content from EPi7 to EPi 7.5. It import the content only but not images. But when i give page stop-publish date then it also import images but i can not see view of images.

i do not want to give page stop publish date. Is there any solution for this ? or must have to give stop publish ? then also how can i see the view of imported images ?

Those images which i add manually are ok. but imported images do not have view.

Export packages generated from will only contain files that are linked to from content (and you need to select the checkbox "Export files the pages link to" when generating the package). You can add individual files by selecting "Export files" and then clicking button "Add". However to export a whole file structure you probably want to programatically attach an event handler to DataExporter (or even better upgrade and run migration tool).

Otherwise old packages containing vpp based files should automatically be converted to new content based files (given that there is a media type for it, see below).

Have you added media types to your project? (see e,g, http://world.episerver.com/Documentation/Items/Developers-Guide/EPiServer-CMS/75/Content/Assets-and-media/Media-types-and-templates/ or examples in 7.5 alloy project)

Yes i added these media types. Actually when i export the page it also export related images and export go well. but when i import in EPi 7.5 it only import only content (text) but do not import images. 

It should import images as well, or at least you should get some error/warning message in the ImportData UI. Have you tried running the import with log4net logging enabled on the site? If so, do you see any errors there?

I am having the same problem. Was this resolved?

I have posted my issue in a new thread here: http://world.episerver.com/Modules/Forum/Pages/Thread.aspx?id=86582&epslanguage=en