Photos keep disappearing from memory card

There is memory built into the camera and additional memory card! Depends how the camera is set to save the photos either to the smaller built in memory or the larger memory card!

Never remove or insert a memory card while the camera is turned on. Try removing the battery, waiting about 30 minutes, and then putting in a freshly charged battery.

Never remove or insert a memory card while the camera is turned on!!!!!!

TRANSFERRING PHOTOS TO COMPUTER
If your photos are stored on the memory card, then removethe memory card from the camera and insert it into an USB memory card reader.Connect this USB memory card reader and memory card into the USB port of yourworking computer. Your computer will see this as an USB Mass Storage Device oran external storage device; you can then open the folder on the memory card andcopy the photos to your computer.Memory card reader is a handy device and is inexpensive. Youcan copy photos from other cameras and you can also download photos off yourmemory card to someone else's computer without the need of installing anyprograms.

Put the card into the camera, use the "Copy" command in the Edit menu to copy the two photos onto the memory card, and then transfer the photos to your computer as you usually do from the memory card.

If they are on the internal memory, they will show up when there is no card in the camera. If you would like to keep these pics, there is a feature called "copy" in the menu which allows you to copy the internal memory to a memory card.

Probably one of two solutions.
First, the memory card should have all the pictures intact. If you are using the camera to review, you may need to just keep going back until the memory card photos show.
Another possibility is that the internal memory supersedes viewing the card memories. You may have to run a USB cable to your computer, download the internal memory photos, and then you can possibly see (on the camera) the memory card photos. It might be a good idea to download those photos to your computer too, if the computer has a memory card slot. Otherwise you will have to go through them and download via the USB again. Once you know the photos are saved, you can either change cards with a new one , or clear the old card and start again.
Good Luck

Check the slide switch on the side of the card....it may have been accidentally moved to the locked position.

If you are using a memory card, take no more pics until you've recovered the photos, take the card out of the camera. This is to reduce the chance of you overwriting some of your "lost" photos. There are many good freeware photo recovery software options that are available to help you recover your photos. This blog article reviews and outlines several of the better ones.

You can recover deleted video from Sony Handycam with camcorder recovery software, recommended asoftech data recovery as it helped me before. download from link below
Download Video Recovery Software

You may refer to this tutorial also
how to recover videos and photos from memory card

I have seen this problem with generic SD memory cards so it could be a faulty memory stick.  Try to get a replacement.  If you want to try to recover the pictures you have taken, I suggest Zero Assumption Recovery (Google for it). Check to see if it is compatible with your camera before downloading.

Barry