No valid instance types found

When I try to launch an instance from a private AMI, I am getting the error

"No valid instance types found" 

The image was created from a snapshot.

Solution : 

Virtualization type by default is Paravirtual, you need to change that type to Hardware-assisted virtualization while creating image from EBS. This will help to fix that error.
 

authorization failed in subversion

Error : authorization failed in subversion, when checkout the repo.

Solution:
Login to svn server
Open svnserve.conf
Uncomment the line "authz-db=authz"

Now check, it should work.