"Probe Height of the current tool" button not active in versatool

I use LinuxCNC 2.9.8, and trying to use versatool to do manual tool change with a tool length sensor and a touch probe.

I do this sequence.

1. Defined tool 99, and load it: M6 T99,
2. Get a pop up window about manual tool change, install the probe in the spindle and press OK,
3. Go to the TLS by pressing the first button in the first row (Go to Tool Setter),
4. Measure the probe height by pressing the second button in the first row (Probe Tool Setter Z Height),
5. Jog above my stock (aluminum), and measure its height by pressing the button in the middle row (Probe Z Height of material),
6. Load a tool: M6 T3,
7. Get the pop up, install the tool and pressed OK

I can see the PROBE HT and BLOCK HT variables set, as seen in the screen shot below.

 

I would then expect to measure the tool height by pressing the first button in the bottom row (Probe Height of the current tool). But I can't, it is not active.

What else do I have to do to be able to measure the tool height?