All, sorry this is such a clumsy procedure.
For cbrockman: I tried your suggestion of uploading the file as .txt, but same error arises that points the finger at my system not being willing to pass the .puz or .txt file up to cruciverb.
For rbe: Changing the filename to .puz won't work. Instead, cut and paste the puzzle contents into a .txt file and then tell Across Lite to open the .txt file. This can be done in two ways: (1) Right click on the .txt file, select "open with", and select Across Lite from the choices. (2) With Across Lite running, click "open" from the menu and select the .txt file. Once you have the puzzle open in Across Lite, you can print it, solve it, or save it as a real .puz.
For coralsun: The best way to proceed is to use the desktop version of Across Lite as described above to create a .puz file. Then open it on your iPad, e.g., by emailing it to yourself and opening the .puz attachment in your iPad email client.