diff -dPNur CCPi-Regularisation-Toolkit-orig/src/Core/regularisers_CPU/FGP_TV_core.c CCPi-Regularisation-Toolkit/src/Core/regularisers_CPU/FGP_TV_core.c
--- CCPi-Regularisation-Toolkit-orig/src/Core/regularisers_CPU/FGP_TV_core.c	2021-12-17 12:17:12.000000000 +0100
+++ CCPi-Regularisation-Toolkit/src/Core/regularisers_CPU/FGP_TV_core.c	2022-09-06 18:52:32.460225737 +0200
@@ -104,7 +104,7 @@
     else {
         /*3D case*/
         float *Output_prev=NULL, *P1=NULL, *P2=NULL, *P3=NULL, *P1_prev=NULL, *P2_prev=NULL, *P3_prev=NULL, *R1=NULL, *R2=NULL, *R3=NULL;
-        DimTotal = (long)(dimX*dimY*dimZ);
+        DimTotal = (long)dimX*(long)dimY*(long)dimZ;
 
         if (epsil != 0.0f) Output_prev = calloc(DimTotal, sizeof(float));
         P1 = calloc(DimTotal, sizeof(float));