Error 15002 means 3 things.
1. Your Time and Date are not correct.
(( If the time/date is correct )) then move to step 2
2. no Space for App to cache, (( reboot box ))
If this didn’t help them move to Step 3
3. You need to check your box has HDCP certifications.
which means no one can copy screen from your HDMI connections.
– to find if you have HDCP compliant box, download app called (( DRM info ))
DRM Info under Google Widevine you should be supported and see the HDCP -1x and max level should be -1x. if you are missing it then your box is not able to load Netflix
If no HDCP you will see your screen as White / Gray / Black Screen or app totally crashing. Those we can not help, we would refer you guys to your box seller or box support team to give you firmware or they need to pay dues to HDCP compliant and get there box certified.
to learn more about Error 15002
https://help.netflix.com/en/node/64618
netflix is quite informative
wont let you down.