I think that there is a display bug in the midi editor => view=>note=>Piano roll notes=>Show velocity handles on notes
The string concerned is 8D4D0B4B0B6A41EE=
Translation in french is : "Afficher les poignées de vélocité sur les notes" which uses some accents
More than that, Reaper seems to crash sometimes :
here is a licecap :
french langpack below(work in progress):