diff --git a/src/inport/ConversionUtils/Solver.java b/src/inport/ConversionUtils/Solver.java
index 0ee32a984ecc22ca033a7b3cf2551223920be7e0..3fe8a6589a9d635fac2952650855cccd1dc80035 100644
--- a/src/inport/ConversionUtils/Solver.java
+++ b/src/inport/ConversionUtils/Solver.java
@@ -133,6 +133,8 @@ public class Solver {
             ProcessBuilder pb;
             boolean isResultsInOutput;
 
+            Process solverProcess;
+
             switch (solverName) {
                 case Chuffed: {
                     pb = new ProcessBuilder("minizinc",
@@ -140,6 +142,7 @@ public class Solver {
                             constraints, minizincData,
                             "-o", solverResults);
                     isResultsInOutput = false;
+                    solverProcess = pb.start();
                     break;
                 }
                 case OrTools: {
@@ -163,6 +166,7 @@ public class Solver {
                     }
                     pb = new ProcessBuilder("external_tools/or-tools_flatzinc_Ubuntu-18.04-64bit_v7.2.6977/bin/fzn-or-tools",
                             flatZincConstraints);
+                    solverProcess = pb.start();
                     break;
                 }
                 case Undefined: {
@@ -185,7 +189,7 @@ public class Solver {
                             return "";
                         }
                     }
-                    pb = new ProcessBuilder(flatZincSolver, flatZincConstraints);
+                    solverProcess = new ProcessBuilder(flatZincSolver, flatZincConstraints).start();
                     break;
                 }
                 default:
@@ -196,7 +200,8 @@ public class Solver {
             isDestroyed = false;
             lock.unlock();
 
-            final Process process = pb.start();
+            final Process process = solverProcess;
+            final BufferedReader br = new BufferedReader(new InputStreamReader(solverProcess.getInputStream()));
 
             Thread killer = new Thread(() -> {
                 lock.lock();
@@ -220,11 +225,9 @@ public class Solver {
                 }
             });
 
-            BufferedReader br = new BufferedReader(new InputStreamReader(process.getInputStream()));
-//            BufferedReader br2 = new BufferedReader(new InputStreamReader(process.getErrorStream()));
-
             killer.start();
-            int exitCode = process.waitFor();
+            String output = br.lines().collect(Collectors.joining("\n"));
+            int exitCode = solverProcess.waitFor();
 
             lock.lock();
             try {
@@ -246,12 +249,10 @@ public class Solver {
 
             if (isResultsInOutput) {
                 try (FileWriter res = new FileWriter(solverResults)) {
-                    res.write(br.lines().collect(Collectors.joining("\n")));
+                    res.write(output);
                 }
                 interpreter.accept(task, solverResults);
             } else {
-
-                String output = br.lines().collect(Collectors.joining("\n"));
 //                String errors = br.lines().collect(Collectors.joining("\n"));
 //
 //                System.out.println("output : " + output);