I wrote to Sakar and asked them ... here's their reply.
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Thank you for contacting us with your inquiry regarding the E 50 message in the Camera.

Please note that the E50 message indicates that there could be a problem with the memory card of the Digital camera. We suggest you to try using a different memory card and check if the problem still persists.

Please feel free to contact us for further assistance.

Thank you for using Sakar International, the leader in technology.

Sincerely,
Richard,
The Sakar International Team
http://www.sakar.com/
1-877-397-8200