When you load a grid and solution you need to load them together. So you would go to File/Load Data File and choose the Tecplot data loader. Then click on the Multiple Files button at the bottom of the dialog, and select both of your files (grid and solution).
Then Tecplot will try to load them.
You do not need to use the "connectivitysharezone=zone_number" parameter in the header of the solution file. In fact, Tecplot will not let you do that because when these files are loaded they will combine to be one zone, rather than two different zones. The header of the Solution file needs to be the same as the header of the Grid file though (except for the FILETYPE parameter of course). And the Solution file does not need the connectivity list since that list is already in the Grid file.
The ConnectivityShareZone parameter is intended to be used when you have one file with many zones defined in it, some or all of which have the same connectivity. For the zones that have the same connectivity, the first of those zones defined in the file must have the connectivity defined in the header and must contain the connectivity list. The rest of those zones can use the ConnectivityShareZone parameter to refer to the first of those zones (by its number) and share its connectivity list.
When you load data into Tecplot, Tecplot numbers the zones 1 to n. It will do the same if you load one file which contains multiple zones. Since the connectivity needs to be defined in a zone BEFORE another zone can share it, then the zone where the connectivity is defined will always come before, and will have a lower zone number than the zone or zones that want to share its connectivity (which is where the ConnectivityShareZone parameter is used).
Tech Support Lead