Atmel Studio Problem

Hello everyone,
I have a problem with the Atmel Studio. I exported my Atmel samr21 project from the online ide to Atmel Studio IDE, however when I try to build the project I get the following error:

------ Build started: Project: Atmel_Blinky22, Configuration: Debug ARM ------
Build started.
Project “Atmel_Blinky22.cppproj” (default targets):
Target “PreBuildEvent” skipped, due to false condition; (’$(PreBuildEvent)’!=’’) was evaluated as (’’!=’’).
Target “CoreBuild” in file “C:\Program Files (x86)\Atmel\Atmel Studio 6.2\Vs\Compiler.targets” from project “C:\Users\iseitani\Downloads\Atmel_Blinky22_atmelstudio_samr21g18a\Atmel_Blinky22\Atmel_Blinky22.cppproj” (target “Build” depends on it):
Using “RunCompilerTask” task from assembly “C:\Program Files (x86)\Atmel\Atmel Studio 6.2\Extensions\Application\AvrGCC.dll”.
Task “RunCompilerTask”
Shell Utils Path C:\Program Files (x86)\Atmel\Atmel Studio 6.2\shellUtils
C:\Program Files (x86)\Atmel\Atmel Studio 6.2\shellUtils\make.exe all
make: *** No rule to make target in.o', needed byAtmel_Blinky22.elf’. Stop.
Done executing task “RunCompilerTask” – FAILED.
Done building target “CoreBuild” in project “Atmel_Blinky22.cppproj” – FAILED.
Done building project “Atmel_Blinky22.cppproj” – FAILED.

========== Build: 0 succeeded or up-to-date, 1 failed, 0 skipped ==========

Any advice??? Is there any other way to flash the r21 board any other ide?

Thank you in advance!