How to use classification Learner in my environment?

I am working on facial expression recognition. i made a dataset contain features & classes of 213 images.

• Step1: Each row of my dataset represents the features of 1 image. so for 213 images 213 rows
• Step2: the last column represents classes like; 1,2,3,4,5,6,7

1. Q1: when i run classification learner and the cross validation is checked the accuracy is very low.
2. Q2: when i run classification learner and the cross validation is not checked the accuracy is good for all classifiers.

• I dont understand why? please help me? if someone has already experienced