Excel Reader works sometime, and not other times

Hello,

 

 

I am running FME 2015, and I have been experiencing some odd behaviour for reading Excel tables,

 

 

I load a feature reader, and I am reading one spreadsheet with numerous columns, 

 

let's say I close the FME workspace, and I open it again the next day, none of the columns are read, and everything appears as null,

 

 

I current workaround, is just re-adding the feature reader... and this does the trick, but its starting to be a pain every time I open the workbench

 

 

Thanks for any help!