You tube error 503 is a server-related issue. Due to overloading, server maintenance, corrupted cache, or a connection timeout, You tube cannot load your video request, thus showing you the You tube 503 error. It always occurs with the reminder of 503 Server Error: Service Unavailable. It can happen in any browser in any operating system, even on your smartphone, or on some applications. Mostly, this You tubea> 503 error occurs since the server is simply too busy or when there’s maintenance being performed on that 
 
 
 
 
 system, even on your smartphone, or on some applications. Mostly, this Youtube 503  error occurs since the server is simply too busy or when there’s maintenance being performed on that.The reason why YouTube error 503 occurs may sound complicated. But you don’t need to worry too Reasons are as follows in most cases, the error winds up being caused by the connector in one form or another.
Connection Timeout
A connection timeout is thought to occur in instances where the APN settings are modified from their default values. this may find Yourself causing some inconsistencies in how the device is ready to access data from other servers. If this scenario is applicable, you ought to be ready to resolve the problem by resetting the Access Point Names to the default values.
Corrupted Cached Data
This is often one among the foremost common triggers on Android devices when it involves this particular error code. because it seems, certain Android builds will trigger this particular issue if the cache data folder becomes corrupted. during this case, you’ll be able to resolve the problem by clearing the cache data.
Server too busy or is undergoing maintenance
It’s also possible that the problem is server-side: Either upkeep or an unexpected outage period that’s affecting your area. during this case, you don’t have any repair strategy at your disposal apart from checking the status of Youtube servers regularly.