I enabled encrypted bit stream with a key and programmed encrypted POF file with ekp file on max10. The program is running well on FPGA. I can not full erase any more the FPGA..

Hi,

Have you enabled the JTAG secure mode in the pof file?

Refer the "3.3.2.2. Generating .pof using Convert Programming Files" from link below,

https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/hb/max-10/ug_m10_config.pdf

Which Quartus Edition(lite/std/pro) , version & Kit used

Thanks,

Vikas