Analysis no longer asks you to set an experiment type when you open a spectrum, but you can set the experiment type at any time. Simply double-click on a spectrum in the sidebar. This will bring up the Spectrum Properties dialog in which you can select the Experiment Type from a drop-down menu. If you want to set the experiment type for lots of experiments at the same time, you can type ET which will bring up a dialog box in which you can specify the experiment types of all your spectra. Usually it should be fairly straight forward to identify the correct experiment type from the drop-down menu. But if you wish, you can click on the gear icon which will allow you to apply various filters as you search for the correct experiment type.
Often it is not necessary to set your experiment types, but it may be required for some data analysis or assignment routines. It also means the program can help reduce your peak assignment options in some instances, e.g. because it knows that two dimensions must have directly bonded atoms or that a particular spectrum can only contain intra-residue peaks.
All the experiment types previously available in V2.4, covering both solution and solid-state NMR experiments, continue to be available. A list of them can be downloaded as an Excel file here.