Did a little searching here on TFP and there is some talk on several threads about the plug not being secure. Also, comments abput recalibrating the unit. There is also a user named circupool here at TFP, maybe give them a PM and ask them to help with your thread.
From an old thread:
mine was reading low salt and I was also getting various no flow errors, etc. Upon further inspection I noticed the plug was not very secure on the unit. I called tech support and they said to bend the tabs on the plug inward. There are three tabs and using a small screwdriver you can bend them in a bit. Then it fit on more snugly and the errors and low salt readings went away.