This is your FONTS.JSON in the config folder. Replace the text with this:

{
    "fontblending" : true,
    "fontwidth" : 15,
    "fontheight" : 15,
    "fontsize" : 15,
    "typeface" : "DejaVuSansMono",
    "map_fontwidth" : 15,
    "map_fontheight" : 15,
    "map_fontsize" : 15,
    "map_typeface" : "DejaVuSansMono",
    "overmap_fontwidth" : 15,
    "overmap_fontheight" : 15,
    "overmap_fontsize" : 15,
    "overmap_typeface" : "DejaVuSansMono"
}


This is your FONTDATA.JSON in the data folder. Replace the text with this:

{
    "fontblending": false,
    "fontwidth": 15,
    "fontheight": 15,
    "fontsize": 15,
    "typeface": "DejaVuSansMono",
    "map_fontwidth": 15
    "map_fontheight": 15,
    "map_fontsize": 15,
    "map_typeface": "DejaVuSansMono"
}