A few things you may try to quickly solve this issue:
1- First try to restart the frame by unplugging the power adapter from the wall outlet during 15 seconds then plug it back.
Wait for the frame to restart and try again.
Is the remote working now?
2- If not try to change the batteries inside the remote and try again.
Be careful when you put the batteries inside as the direction of each battery is important.
Does it work now?
If it is still not working and your frame I less than 2 years old, contact us through the customer support link at the upper right corner on the main page of the www.pix-star.com web site.
if your frame is older than 2 years then the remote is out of the warranty period so you need to buy a new one from our shop using this link:
https://shop.pix-star.com/collections/all
Enjoy your pix-star.