source/blender/editors/interface/regions/interface_region_tooltip.cc

@@ -28,6 +28,7 @@
 
 #include "DNA_userdef_types.h"
 
+#include "BLI_fileops.h"
 #include "BLI_listbase.h"
 #include "BLI_math_color.h"
 #include "BLI_math_vector.h"
@@ -1724,6 +1725,12 @@ static void ui_tooltip_from_vfont(VFont &font, uiTooltipData &data)
     return;
   }
 
+  if (!BLI_exists(font.filepath)) {
+    UI_tooltip_text_field_add(
+        &data, TIP_("File not found"), {}, UI_TIP_STYLE_NORMAL, UI_TIP_LC_ALERT);
+    return;
+  }
+
   float color[4];
   const uiWidgetColors *theme = ui_tooltip_get_theme();
   rgba_uchar_to_float(color, theme->text);

source/blender/imbuf/intern/thumbs_font.cc

@@ -49,6 +49,9 @@ bool IMB_thumb_load_font_get_hash(char *r_hash)
 ImBuf *IMB_font_preview(const char *filepath, uint width, const float color[4])
 {
   int font_id = (filepath[0] != '<') ? BLF_load(filepath) : 0;
+  if (font_id == -1) {
+    return nullptr;
+  }
   const char sample[] = "ABCDEFGH\nabcdefg123";
 
   BLF_buffer_col(font_id, color);