Your G-Tilt file may be missing a sensor (probe) serial number.
G-Tilt marks the start of every survey with a *. Count six lines down from the *. You should see a serial number or at least some sort of text. Go through each of your G-Tilt files. Look for the * and count six lines down. Enter the sensor serial number in that 6th line (or just type 12345). Look for additional *s in the file and check that the sixth line after each one has a serial number. You can put any text tha fIf you have multiple surveys in the file, you’ll have to make multiple entries.
* —- marks the start of a survey
070685 —- survey date
1327 —- time hhmm
1400 —- not used by DMM
Top of clamp —- not used by DMM
31.2 —- not used by DMM
12345 —- sensor serial number. line must not be empty