BUILD FAILED Unable to resolve project target 'android-21'

I get

BUILD FAILED
C:\ProgramData\Uno\SDKs\AndroidSDK\tools\ant\build.xml:542: Unable to resolve project target 'android-21'

when I try to build for android, what’s going on?

Have you installed the android tools using fuse install android as our android export guide suggests?

yes, in fact, i’ve exported and previewed to android before, it’s just on this particular occasion

Hi

Please run fuse install android again (it doesn’t take long), since we have changed our required SDK platform version from 19 to 21.

My experience is that you also need to remember to run the command as administrator.

Liam, please don’t do that. It should never be neccessary, and may lead to problems later.

Why did you have to run as adminstrator, and was that on OS X or Windows.