deleting unsupported pictures from samsung E7

[nalini prabhakaran]

Am unable to delete syned pics from my android phone.delete option is not appearing. Wheni tried am getting a message that they are unsupported files.how is that possible

 

[nalini prabhakaran]

Unable to delete wifi synced pic from the gallery. Delete option is not appearing.when tried getting a message that they are unsuppoted files.how to do it