I built a vanced version for android 5.1.1 that does not pop up an update youtube error. Based on youtube vanced 16.29.39 (sdk21)
-updated it wia d4n3436's modded revanced patches(22.06.2023) and youtube 16.40.36
!!! error 400 semi fix updated again !!!!
Actually there is a fix but also there isnt, For the videos You have to add them on a playlist( for example watch later press on the 3 down right left to text > click add to watch later > there will be a pop up saying go to list click on it> then you can play videos from the playlist) you have to play videos from the playlist, Otherwise it wont open the videos, videos in the main screen are not clickable. For now its the best i can do.