Having trouble Measuring Frequency of Simulated 555 MV circuit

I am trying to simulate the circuit inside of a 555 timer. I would like the post-process window to show the eventual frequency of V(OUT) once the waveform settles. Not having any success. The directives I used are listed below.
.tran 100m
.plot V(TRIG) // Vc1 voltage at C1
.plot V(Q)
.plot V(OUT) // Q not signal
.meas frequency V(OUT) at T=50m to T=100m

Update: Forgot to show what displays in pre-processor window. V(OUT) plots fine and the frequency should be about 100Hz. But what the pre-processor window does not show this. What it does show is below:
.meas freq v(out):
4.81838 0.1

this syntax is incorrect? at T=50m to T=100m should return error.

This syntax indicates measuring the last data point of V(out) (your simulation runs for 0.1s, measuring V(out) data at 0.1s, and freq is simply the label for this data measurement, unrelated to frequency measurement.
To measure frequency, we normally measure the time between two rising edges to calculate the period and then calculate the frequency.