Why would the Add Value button be grayed out for a tool parameter?

Discussion created by NeoGeo on Sep 3, 2013
Latest reply on Sep 10, 2013 by NeoGeo
Any guesses as to why the "Add Value" button would be grayed out for a parameter so that you could not enter a parameter, but it is a required parameter so you have to have it to run the tool?  (It is just a string).

Update: There appears to be a bug where it cannot handle entry of multivalue strings.  If you turn off multivalue, you can enter a value, but then it does not work because it is supposed to be multivalue so it can populate a Python dictionary object. 

At 10.0, one did not have to run the tool from the Desktop, only browse to it to create a geoprocessing service from it and it worked fine.  Now one apparently has to run all of their server based tools from the Desktop just to be able to create a Geoprocessing Service from them as far as I can tell.