magento2 not able to generate cache images

magento2 not able to genrerate cache images in folder /pub/media/catalog/product/cache/ inside that folder blank all commands working fine from i end permission looks fine in uubuntu server php5.6 and php7 install you have to do via tea,mviewer i cant share ppk file also if u can do then bid please because we both will waste our time. I am also magento developer but cant solve this issue , if u can . After that u are my expert :) One more thing low budget prefers. Note : 1. I tried whole day with lot of tricks failed 2. In localhost /magento20 folders works fine and regenerated but not on server 3. Dont put links and all plz make a simple bid "yes i can do" with start and some dummy content which does not matter for me 4. Also Hope you know aws and ec2 instance