crash on terminal

[dhekrazaied]

uiauto exec Test-1.js

Script: Test-1.js
/Library/Ruby/Gems/2.0.0/gems/uiauto-0.2.1/lib/uiauto/instruments.rb:82:in join': no implicit conversion of nil into String (TypeError) from /Library/Ruby/Gems/2.0.0/gems/uiauto-0.2.1/lib/uiauto/instruments.rb:82:indefault_application'
from /Library/Ruby/Gems/2.0.0/gems/uiauto-0.2.1/lib/uiauto/instruments.rb:18:in initialize' from /Library/Ruby/Gems/2.0.0/gems/uiauto-0.2.1/lib/uiauto/runner.rb:48:innew'
from /Library/Ruby/Gems/2.0.0/gems/uiauto-0.2.1/lib/uiauto/runner.rb:48:in run_one' from /Library/Ruby/Gems/2.0.0/gems/uiauto-0.2.1/lib/uiauto/runner.rb:34:inrun'
from /Library/Ruby/Gems/2.0.0/gems/uiauto-0.2.1/lib/uiauto/cli.rb:71:in exec' from /Library/Ruby/Gems/2.0.0/gems/thor-0.19.1/lib/thor/command.rb:27:inrun'
from /Library/Ruby/Gems/2.0.0/gems/thor-0.19.1/lib/thor/invocation.rb:126:in invoke_command' from /Library/Ruby/Gems/2.0.0/gems/thor-0.19.1/lib/thor.rb:359:indispatch'
from /Library/Ruby/Gems/2.0.0/gems/thor-0.19.1/lib/thor/base.rb:440:in start' from /Library/Ruby/Gems/2.0.0/gems/uiauto-0.2.1/bin/uiauto:4:in<top (required)>'
from /usr/bin/uiauto:23:in load' from /usr/bin/uiauto:23:in

'
How can I fix that??

[parikhparth23]

how to fix this...im also getting the same error!