How to fix YouTube error not playing when using WiFi

[AC Question]

I am using Vodafone tab 4.4.1 android version since I bought the device was working effectively until I run out of space then I reset the device back to factory settings when I connect to WiFi again the apps I have can not play through WiFi the read error server 945 but I use Google to search but wouldn't play video same for YouTube please help I use this also for my studies as well