Mis typo at
#define LV_OBJ_X_NAME “lv_templ”
To
#define LV_OBJX_NAME “lv_templ”
Version Dev6.1
https://github.com/littlevgl/lvgl/blob/dev-6.1/src/lv_objx/lv_objx_templ.c#L26
Version Dev7.0
https://github.com/littlevgl/lvgl/blob/dev-7.0/src/lv_objx/lv_objx_templ.c#L26