I am connecting Quality Center to QTP.

I succeeded to connect QTP with QC.
E.g. I could get a QTP test from QTP into the test plan in QC, and then link it to the test lab.
If I run the test starting from QTP, I get test results which are visible in QC.

However the other way around does not work:
- In QTP I set the checkbox "Allow other Mercury products to run tests and environments" to ON.
- I shared the Mercury Interactive Program Files to give the QC server access.
- I selected the QTP host on the Run on host settings in QC
But: If I run the QTP test from the QC testlab I get the error message: "No available hosts on this group".

How is this possible?