diff --git a/all.sas b/all.sas
index 739e861..93df8ed 100644
--- a/all.sas
+++ b/all.sas
@@ -19807,6 +19807,11 @@ data _null_;
   put '%end; ';
   put ' ';
   put '%else %if &action=ARR or &action=OBJ %then %do; ';
+  put '  %if "%substr(&sysver,1,1)"="4" or "%substr(&sysver,1,1)"="5" %then %do; ';
+  put '    /* functions in formats unsupported */ ';
+  put '    %put &sysmacroname: forcing missing back to NULL as feature not supported; ';
+  put '    %let missing=NULL; ';
+  put '  %end; ';
   put '  %mp_jsonout(&action,&ds,dslabel=&dslabel,fmt=&fmt,jref=&fref ';
   put '    ,engine=DATASTEP,missing=&missing,showmeta=&showmeta ';
   put '  ) ';
@@ -20603,6 +20608,11 @@ run;
 %end;
 
 %else %if &action=ARR or &action=OBJ %then %do;
+  %if "%substr(&sysver,1,1)"="4" or "%substr(&sysver,1,1)"="5" %then %do;
+    /* functions in formats unsupported */
+    %put &sysmacroname: forcing missing back to NULL as feature not supported;
+    %let missing=NULL;
+  %end;
   %mp_jsonout(&action,&ds,dslabel=&dslabel,fmt=&fmt,jref=&fref
     ,engine=DATASTEP,missing=&missing,showmeta=&showmeta
   )
diff --git a/server/ms_createwebservice.sas b/server/ms_createwebservice.sas
index 62f113a..9b4cd05 100644
--- a/server/ms_createwebservice.sas
+++ b/server/ms_createwebservice.sas
@@ -390,6 +390,11 @@ data _null_;
   put '%end; ';
   put ' ';
   put '%else %if &action=ARR or &action=OBJ %then %do; ';
+  put '  %if "%substr(&sysver,1,1)"="4" or "%substr(&sysver,1,1)"="5" %then %do; ';
+  put '    /* functions in formats unsupported */ ';
+  put '    %put &sysmacroname: forcing missing back to NULL as feature not supported; ';
+  put '    %let missing=NULL; ';
+  put '  %end; ';
   put '  %mp_jsonout(&action,&ds,dslabel=&dslabel,fmt=&fmt,jref=&fref ';
   put '    ,engine=DATASTEP,missing=&missing,showmeta=&showmeta ';
   put '  ) ';
diff --git a/server/ms_webout.sas b/server/ms_webout.sas
index 504ec6b..e917c7d 100644
--- a/server/ms_webout.sas
+++ b/server/ms_webout.sas
@@ -100,6 +100,11 @@
 %end;
 
 %else %if &action=ARR or &action=OBJ %then %do;
+  %if "%substr(&sysver,1,1)"="4" or "%substr(&sysver,1,1)"="5" %then %do;
+    /* functions in formats unsupported */
+    %put &sysmacroname: forcing missing back to NULL as feature not supported;
+    %let missing=NULL;
+  %end;
   %mp_jsonout(&action,&ds,dslabel=&dslabel,fmt=&fmt,jref=&fref
     ,engine=DATASTEP,missing=&missing,showmeta=&showmeta
   )