diff --git a/src/mcx_utils.c b/src/mcx_utils.c
index 6ccab3fc..957cd53f 100644
--- a/src/mcx_utils.c
+++ b/src/mcx_utils.c
@@ -1758,15 +1758,15 @@ void mcx_prep_polarized(Config* cfg) {
  */
 
 void mcx_prepdomain(char* filename, Config* cfg) {
-    if (cfg->isdumpjson == 2) {
-        mcx_savejdata(cfg->jsonfile, cfg);
-        exit(0);
-    }
-
     if (filename[0] || cfg->vol) {
         if (cfg->vol == NULL) {
             mcx_loadvolume(filename, cfg, 0);
 
+            if (cfg->isdumpjson == 2) {
+                mcx_savejdata(cfg->jsonfile, cfg);
+                exit(0);
+            }
+
             if (cfg->shapedata && strstr(cfg->shapedata, ":") != NULL) {
                 int status;
 
@@ -2709,7 +2709,11 @@ int mcx_loadjson(cJSON* root, Config* cfg) {
         }
 
         if (!flagset['B']) {
-            strncpy(cfg->bc, FIND_JSON_KEY("BCFlags", "Session.BCFlags", Session, cfg->bc, valuestring), 12);
+            char* bc = FIND_JSON_KEY("BCFlags", "Session.BCFlags", Session, NULL, valuestring);
+
+            if (bc) {
+                strncpy(cfg->bc, bc, 12);
+            }
         }
 
         if (!flagset['b']) {
diff --git a/src/pybind11 b/src/pybind11
index a8b3ff30..2d59b43c 160000
--- a/src/pybind11
+++ b/src/pybind11
@@ -1 +1 @@
-Subproject commit a8b3ff30f9649459021adc80f98a945d3ac675a5
+Subproject commit 2d59b43cbf8793119fb92726ce8eb33441469e3e