Recently, Avast gave me a message saying that I should update the virus definitions, so I went to the update section to do just that. However, every time I try to update either by clicking on the “update engine and virus definitions” button or the “update program” button, it tries to update for about two seconds maximum before stopping, displaying the message: “Last encountered error: the package is broken”
Um…what do I do? o.o;
Which version avast are you using?
Hello Mongrel614: You could try a repair of Avast. Go to Control Panel, Add and Remove Programs and choose Avast. Then click Change/Remove. Scroll ‘down’ the options and choose “Repair”. When finished reboot computer. Now try to update. See if that solves your problem. 
Hey guys, I uninstalled and reinstalled and it fixed the problem. Thanks for your help though =)
Hello.
I had the same problem in updates, so I uninstalled Avast and tried to install again, but everytime I try, an error occur. Log shows “Return code: 0x20000011 [The package is broken.]”
Sorry, I just installed it successfully. I removed with the aswClear5 and installed in secure mode.
Please uninstall avast via add remove programs then reboot into safe mode and run the removal tool http://www.avast.com/uninstall-utility then reboot back into normal mode, run ccleaner and re install avast, make sure any other av’s you have or have had are deleted.