Index: /issm/trunk-jpl/src/m/solve/WriteData.py
===================================================================
--- /issm/trunk-jpl/src/m/solve/WriteData.py	(revision 17166)
+++ /issm/trunk-jpl/src/m/solve/WriteData.py	(revision 17167)
@@ -201,5 +201,9 @@
 
 		#first write length of record
-		fid.write(struct.pack('i',4+4+8*s[0]*s[1]+4+4))    #2 integers (32 bits) + the double matrix + code + matrix type
+		recordlength=4+4+8*s[0]*s[1]+4+4; #2 integers (32 bits) + the double matrix + code + matrix type
+		if recordlength > 2^31 :
+			raise ValueError('field %s cannot be marshalled because it is larger than 4^31 bytes!' % EnumToString(enum)[1])
+
+		fid.write(struct.pack('i',recordlength))  #2 integers (32 bits) + the double matrix + code + matrix type
 
 		#write data code and matrix type: