I'm currently using ModelBuilder to automate a process on about 400 shapefiles, but I'm having trouble to get it working. First, I create a study area (buffer) and then clip land use area. Then I select the land use classes of interest and calculate 21 radius values which I want to use to run Multiple Ring Buffer (MRB). Below, you can find the model including the error I get when running it. I don't know why it's trying to convert a string to float at all, because all the radius values are stored as Double and in the Get Field Value command I also specified the data type Double. Does anyone know why this occurs and how to fix this error?
Here you can see the attribute table from which Get Field Value draw the radius values (rCircle00, ... rCircle20):
And this are the parameters I set for the MRB (1) before running the model and (2) what it looks like after running the model when I get the error. I'm not sure about the (1) Distances = 1 which was generated when I connected the Collect Value Output to the MRB. However, it seems that the distances were passed correctly, as seen in (2).