After upgrading Workspace Streaming to 7.6 the applications with packages that were compiled in older versions may fail to stream to Windows 10 computers. However packages created in the new version do stream successfully.
Error Code 10013: This package does not support this operating system version.
The package format changes between versions and packages created in older versions that do not support Windows 10 will not have the appropriate format to stream to Windows 10.
Recompile the old packages in the new version of Virtual Composer and then reimport them into the Streaming Console. The try streaming the applications again.