Gallery app Problem

[Pratik Pawar]

My lil sis bought Micromax Unite 3 Q372, 3 months ago, with Android 5.0.2
since few days, the Gallery app is not working, not even starting, whenever we open it, an error message occurs,

*i.imgur.com/4tI7jGK.png

all the pics are there, coz the photos app opens, & they can be seen there,
what could be the reasons, any solutions plzz.. thanx in advance

 

[sling-shot]

One thing to try is clearing all the data of Gallery. Go to Apps > All and locate Gallery there. Go in clear data. Restart.