My WII fit freezes every time I start it.

Yes, it's completely normal. To avoid this, try to take the BMI test at the same time everyday. If you have a big meal in between the weights, it might say that.
Also, the batteries on the board may be running low. Try with some new ones and see if the problem persist.
Also, try keeping the Wii Balance board on a flat hard surface, such as the floor. Do not use it on thick carpets since it might report bad measurements.
Hope this helps.

Replace your Wii Fit Plus board and/or DVD disk. I had the same problem. The seller has gave me a new Wii Fit Plus set (instead of the 1st one), and everything was OK. I don't know if the problem was in the board or in the DVD disk.

Sounds like a scratch or finger print on the disk.

Wii Fit? The problem can be that your Wii is modded (IF ITS MODDED), or that the disc contains scratches.

You need to step off the pad, wait until it tells you to step on. Then you push A to conduct the body test. If your pad is turned off push the button on the front of the wii fit pad then repeat the first steps i described.

yes. Fo the Wii Fit Board Test.

If your Wii Fit Balance Board is on carpet, be sure to use the extra foot pads that came with your board. If your carpet is really thick, you may need to use a flat woodend board to set the balance board on.

Finally, make sure that you are NOT using your child's Miii to do your own balance test. Each user of Wii Fit must use their own Mii character.

If you don't like my suggestion, please don't rate this suggestion a '1'. If my suggestion doesn't help, the problem may exceed the scope of what can be answered here. You will need to contact Nintendo directly through their website and open a problem ticket.

Good Luck!

This process only deletes Miis so that you can add new ones,
up to a maximum of 8.

Nintendo provides no advance notice that there is a limit of 8 players.

1. Go to the Wii Fit screen displaying all of your current Miis.
2. Select the Mii you want to delete.
3. Keep hitting the A button to go through all the extraneous jazz-ma-tazz nintendo inflicts upon us
until you come to the calendar page with the options BODY TEST and TRAINING at the bottom.
On this page you will see USER SETTINGS in the upper right-hand corner.
4. Select the USER SETTINGS page (push the A button).
5. Select DELETE USER DATA (push the A button).
6. Select YES to confirm that you want to erase the data.

I found this process very counter-intuitive as it required me to select the Mii that I wanted to delete,
then act as if I were going to use this Mii, before giving me an option to manage the settings for that Mii.

The process for using a memory card to save Miis has been impossible so far.
I purchased a Wii memory card, but cannot figure out how to bring the data from the memory card
back into the Wii Fit game.

Please be a bit more detailed in the problem. The Wii Fit Balance Board is very sensitive to weight shifts. Ensure that you allow the board to calibrate properly. To do this, I would suggest the following steps:

1) Place balance board on a sturdy, flat, smooth surface. If you have average-shag carpet, be sure to use the little adapters that fit over the feet. If the carpet is too thick, then it will NOT work properly. You may want to consider a small piece of plywood or something similar to set between the carpet and Balance Board.

2) Don't step onto the board until it has calibrated (this is when the board establishes its zero point). It will clearly say "Starting Up" followed by "Ok, Step On." After this, you can generally stay on the board unless a particular routine asks you to get off or for some reason it needs to recalibrate.

3) Finally, you must ALWAYS back out all the way to the Wii Fit Plaza (where you pick your Mii) if you change players. Once the board is configured for one player, it will only be suitable for that individual. Its sensitivity is based on an individuals weight. For instance, if the board is calibrated for a 3-year old's Mii, and an adult decides to play any of the routines on that Mii, the board will be over sensitive (calibrated for the lighter weight). Conversely, if an sdult's Mii is selected and a child plays a routine, the board may not detect the movement.

I hope these steps will help. If not, please offer a step by step explanation on what you are doing and I will try to reassess your situation.

Thanks!

Did you buy it new? If so, it can sometimes play a few tricks. What I do, is restart the Wii, Go to start either the disc channel Wii Fit, or the Wii Fit channel. Do either the body test, then do it again straight after. Test it now, it should come up as all working. If not, you may have to ring Nintendo.