Failed to load os image on colibri imx6

Dear colleagues
I get this error when I put large file on flash disk:

Invalid image signature
Error: Failed to load Os image from SD/MMC
Info: OEMReportError Reason 0xfffffffa

Help me please

Are you talking about image size when refer to "large file? If so, please check this article Maximum image size - Technical Support - Toradex Community

How do you flash the image? Do you use bootloader commands, update tool or easy installer?