Haskell Ambiguous type variable error message. Clueless..

haskell-error-001

Ambiguous type variable ‘a0’ arising from a use of ‘getLast’
      prevents the constraint ‘(Read a0)’ from being solved.
      Relevant bindings include
        transferTXIDM :: Maybe a0 (bound at bin/FaeServer/App.hs:93:5)
      Probable fix: use a type annotation to specify what ‘a0’ should be.
      These potential instances exist:
        instance (Read b, Read a) => Read (Either a b)
          -- Defined in ‘Data.Either’
        instance forall k (s :: k). Read (Proxy s)
          -- Defined in ‘Data.Proxy’
        instance Read ExitCode -- Defined in ‘GHC.IO.Exception’
        ...plus 34 others
        ...plus 102 instances involving out-of-scope types
        (use -fprint-potential-instances to see them all)
    • In the expression: getLast Nothing Just
      In the expression: getLast Nothing Just $ getParams "transferTXID"
      In an equation for ‘transferTXIDM’:
          transferTXIDM = getLast Nothing Just $ getParams "transferTXID"
   |
93 |     transferTXIDM = getLast Nothing Just $ getParams "transferTXID"
   |                     ^^^^^^^^^^^^^^^^^^^^