Apparently Microsoft has temporarily removed the Windows RT 8.1 update from the Windows Store due to the fact that it was causing updating issues to a “limited” number of users. This information first popped up in the Microsoft forums by an employee going by Reagan_L username.

If you were planning to update to your Surface RT to Windows RT 8.1 this weekend and you couldn’t find the update in the Windows Store, you now know why and you don’t have to keep search for a solution.

In the forum Reagan_L states:

For now there is not specific details to what the real problem is, on October 17th the software giant released Windows 8.1 for Windows 8 and Windows RT, some users were experiencing some issues, but nothing that we didn’t already expected. However for the company to remove such an important update so soon the problem has be really serious.

Windows RT 8.1. Microsoft is investigating a situation affecting a limited number of users updating their Windows RT devices to Windows RT 8.1. As a result, we have temporarily removed the Windows RT 8.1 update from the Windows Store. We are working to resolve the situation as quickly as possible and apologize for any inconvenience. We will provide updates as they become available.

I’ll keep you post it as more information becomes available.

Update: Here is Microsoft Support official statement: 

Windows RT 8.1 update temporarily removed from Windows Store. Situation affecting small number of users. Working to resolve ASAP.

— Microsoft Support (@MicrosoftHelps) October 19, 2013

Update: As we still waiting for the Windows RT 8.1 update to appear once again in the Store, Microsoft just made available the Surface RT Recovery Image to fix this problem.

Source Microsoft via Windows Observer