Good Morning gebauman,
Have you got the software installed on any other computer? We have tried something similair before, not with the positive.u file but with other files that have been corrupted.
If you have it, you can always copy the file from another computer and replace the positive.u tune file. This should sort out your problem.
I have never used a 6150B but on the 5975 and 5975T there is a directory that contains default tune files:
You can click on the device you are after and find the default tune files.
I'm not sure on the directory on your MS though but I'm sure there will be something similair.
The previous reply from my colleague gchaplain is on the right track. Basically for the G6150B, the tune files reside at C:\Chem32\1\6150btun\atunes.tun. The \1\ in this string refers to the instrument number so if you ave multiple instruments configured you may see a different number:
If you see this error again, let us know and we can send you the missing file or complete directory.
Or maybe, once you have tune files that you are satisfied with you can make a backup of these files just in case.
I tried multiple times to replace the atunes file both from saved files on the same machine and also from other 6150's. We even reinstalled Chemstation on a new computer. In the end we were able to finally rid the system of this error by updating the 6150 firmware.