This error means that the version of the run-time, cblrtss.dll that is being loaded is not the correct version. This normally is caused by deploying an application on a Server 5.1 product version that is not at the same level as the Net Express version with which it was compiled.
Your mfsupportinfo log does not show that an actual Server product has been installed on that machine but that the PATH might include an older version.
Make sure that the Server 5.1 version is the same as the NX version.
Thanks.