Please make sure you are using a standard microSD/microSDHC memory card (class 4 or class 6) and NOT an Ultra card (above class 6). The memory card should not have printing with the word "Ultra" or ‘C’ symbol with 10 in it or ‘U’ symbol with 1 or 3 in it.
The size compatibility is 8GB - 32GB.
If you use an ultra memory card it will not recognize it, or it may record one or two videos but not beyond that point. In any case it does not damage the memory or the camera system.
Please see some guidelines on what to look out for (circled in yellow) in buying microSD memory card.