There's usually two reasons you can't transfer your pensions
We're still contacting your provider. This is why your pension is greyed out and you can't select anything. We're just checking that your pension is okay to transfer and you have no valuable guarantees of special features you'd lose as a result of transferring. Getting a response from your provider can take days or weeks depending on who it is.
We're unable to transfer this type of pension. This could be for a number of reasons, but most likely the pension scheme is something we're unable to giv advice on (e.g. final salary pension).