Memory not working in my D50.

I had the same exact problem. I did some research on this issue. Apparently The D50 will not work with a memory card above 2gb. I swapped my 4gb to the 2gb and solved the issue. Good luck.

I had the same problem. I was try to use a memory card higher than 2GB. I was told that the older model D50 can not handel any thing higher.

1. Use Nikon approved card
2. Check the mediea card for Damage
3. format the memory card or delete files on the card

That there is a problem with the camera 'accepting' the memory card. You could try removing the card and then reseating it and that sometimes works.
You may could reset the camera and then reformat your memory card or cards.

Camera resetting can be done using the approach on page 120 in the camera manual.
Many professionals reformat their cards every time they've downloaded their photos. Reformatting should be done as per the manual.

THERE IS A "LOCK" LEVER ON YOUR MEMORY CARD----->UNLOCK IT (when it's locked, you cannot read or write information to it, but the lever is often bumped accidently

You haven't provided enough details to be sure of the problem, but I suspect you have either bought a new memory card that is either the wrong type or too large for that camera. If it is still the original memory card that you first used with your camera, try reformating the card.

Hi, I am not an expert. But I just had the same problem. Far as I can tell the D50 does not support SDHC, it was made before the SDHC technology came out. Pentax offers an upgrade to support it for their cameras, so perhaps Nikon will too, though I haven't found anything on it yet. My own solution was to pull my 2GB card out of my phone, put it in its adapter and stick it in my camera, works great. I put an older smaller card into my phone, now all my things are happy. This likely won't work for most people, but worked for me. If I see something about upgrading the camera I will put it on here.

No, the D50 will not (as you've discovered) accept an SDHC memory card (anything bigger than 2gb is SDHC). I haven't found a firmware upgrade for the D50 to rectify this issue, either. I own a D50 also, and love it, but bigger cards would be nice.

that means that there is something wrong with your memory card. that or its too big. i got a 4gb memory card last month and it was too big. i think the biggest size you can get is 2gb. 

The first memory card I had, had gotten corrupted, and the D50 can only take 2GB memory cards and below. the 2nd one i had bought was a 4GB memory card. I just had to get a new low capacity one.