Importing Float data into Rowers allows you to see more data from the rowing machine that ever before.
To import the data it is import that session from Float matches the session in Rowers.
E.g. If you did 2000m in Float the session in Rowers should have a single piece of 2000m in the work structure.
If the session in Float is different to the work structure in Rowers then session won't be able to be imported.