Parse errors in parameter files are hidden among other output, and are thus difficult to spot. This example shows this:
cactus::cctk_itlast = 3 ; ActiveThorns = "HDF5"
The problem is that the error message is output among the activation messages. If the parameter file is long and the syntax error is in the beginning, then several hundred lines may be output after the error message, which makes it very difficult to spot it.
The parsing errors should be output in the same way as other parameter errors, which are prefixed by WARNING etc.