Emeraldnum and playcredits can only be set when initialising a new gamedata

src/deh_soc.c

@@ -4086,16 +4086,30 @@ void readcupheader(MYFILE *f, cupheader_t *cup)
 				cup->cachedlevels[CUPCACHE_PODIUM] = NEXTMAP_INVALID;
 			}
 			else if (fastcmp(word, "EMERALDNUM"))
+			{
+				if (!mainwads || (refreshdirmenu & REFRESHDIR_GAMEDATA))
 				{
 					if (i >= 0 && i <= 14)
 						cup->emeraldnum = (UINT8)i;
 					else
 						deh_warning("%s Cup: invalid emerald number %d", cup->name, i);
 				}
+				else
+				{
+					deh_warning("You must define a custom gamedata to use \"%s\"", word);
+				}
+			}
 			else if (fastcmp(word, "PLAYCREDITS"))
+			{
+				if (!mainwads || (refreshdirmenu & REFRESHDIR_GAMEDATA))
 				{
 					cup->playcredits = (i != 0 || word2[0] == 'T' || word2[0] == 'Y');
 				}
+				else
+				{
+					deh_warning("You must define a custom gamedata to use \"%s\"", word);
+				}
+			}
 			else
 				deh_warning("%s Cup: unknown word '%s'", cup->name, word);
 		}