Hi,
If we have made any chagnes from site admin side of wordpress blog then we need to upgrade all the blogs. We can do it simple with running upgrade script. These are the steps to do that:
1) Login into wordpress MU site admin.
2) Click on Upgrade option from site admin section [See Image].

3) Click on Upgrade site button to upgrade all the blogs. [See Image]

That’s it!
Thanks,
Shane G.
Popularity: 5%