some .asax .svc files become empty after deploy

some .asax .svc files become empty after deploy

We use msdeploy to push our services(about 10 services) to AWS EC2.
Here is my step:
1.Create instance in AWS.
2.Deploy all services to AWS one by one.
3.Terminate the instance created in step 1.
4.Snap a new image based on the terminated instance.
5.Launch instances based on the new image.
It's strange that after deploy (step 2), the Global.asax and *.svc files
in the last service become empty.
I checked the source files in PackageTmp, they are not empty.
Does anyone have idea about this?
Thank you.