Building upgrades

[RuthieHallam]

I have collected all the items needed to upgrade a building but the 'build' button is greyed out - why?

[kooky panda]

See this thread
http://forums.teamlava.com/showthread.php?45863-Upgrading-buildings&p=538213&viewfull=1#post538213

Try restarting your device. Also check to make sure you do have all the items needed.
If you can, post a picture in the above thread.