The Leica S2 does not support SDXC or UHS memory cards, this is most likely your problem. You need to use an SDHC card, which comes in sizes of 32GB or smaller. You cannot use an SD card larger than 32GB in the S2 or S2-P. I would recommend Transcend Class 10 32gb SDHC cards, that is what I have used for a number of years in the S2 without any problems at all.
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