Hi.

I was seeing the same problem as greymatter314 in my n810. App installations would all fail at the download stage. The error was "Downloading [program name] failed." I was seeing a 'memory card error' whenever I plotted a route in Wayfinder, and I could no longer add POIs (points of interest) due to same 'memory card error.

My internal card had somehow become read-only. Here's what I did to get things running again. I only wish I knew why my internal card became read-only. Anyway.

I tried to use the file manager utility to copy any files from the internal card to the external card, but the big map folder was too large. Not really knowing what those files contained made me a little nervous about deleting them, so I started Wayfinder and wrote down my license code (under the About menu) in case I had to reinstall the whole program.

I then used the File Manager utility to reformat the internal memory card. Once that was done, I immediately installed 'becomeroot.' My download and install went smoothly. (Not to use it for this problem, but it is the app that first gave me trouble downloading).

Next, I started map, but my maps were no longer there. I plugged my n810 into the charger (so I could leave wifi running for hours) and re-downloaded the map data. I didn't need to use my license number to do this, but I had to leave it running a long time, as it was a pretty big file-- the progress bar for the download was about 1/4 across after 30 minutes so I left it and went to bed. In the morning my maps were back and all my POIs were gone but I can reconstruct those from memory and with a little help maybe from GoogleEarth.

[edited to add] I did need my wayfinder license number after all-- I had to open Map, got to the menu and select About Map > purchase license. At the next screen I entered my license number and I could use the navigation software again.

Your mileage may vary, good luck.

-- killick