When your while loop reaches the last line (iteration i=8), the VI writes 0 to the analog output. The VI also calculates the difference between lines 8 and 9. The time in line 8 is 10 s, line 9 doesn't exist, so the index array returns 0 s. The calculation is: 0 s - 10 s = -10 s. Multiplying this by 10 results in -100 iterations for the analog input's FOR loop. Since the FOR loop isn't executing, no value is read from the analog input.
You can either add an extra line with 10, 1, and 0, or something similar. Alternatively, you can define an exception for negative iteration numbers and read at least one measurement from the analog input. Or you make an exception only for the last line.
