There are four things that you need to check:

1. Are you licensed for more than 1 concurrent run. his can be found in Lab Management, PC Licenses

2. Did you set up the ''Concurrent Run limits'' in the project settings for each project?

Please do this:

* Login to Lab management

* Select ''Lab Settings'' drop down list

* Select ''Project Settings''

* Find you project name

* Verify the ''Concurrent Run Limit'' is a number in the range of 1 to 999 (based on your license)

3. In Lab Management, under Hosts, you have to have multiple Host machines set up as
Controller machines. Recommend setting them as Controllers and Data Processors

4. Verify the second is not trying to use the same controller, data processor and LGs as the first test

**Note:**
**Performance center as run and track multiple tests at the same time. However the Controller, Data processors and LGs machines can ONLY run one test at time**.

**Example:**
For test **Alpha** you need:

1. Controller machine
2. One LG machine
3. A Data Processor machine ( can also be the controller )

For test **Bravo** you need:

1. Controller machine
2. One LG machine
3. A Data processor machine ( can also be the controller )

To run both test at the same time, the machines used for test *Alpha* can NOT be used for Test *Bravo*. Thus for the above example you need 3 machines for test *Alpha* and 3 different machine for *Bravo*. For a total of 6 machines to run both.