diff --git a/CHANGES/v2.0.txt b/CHANGES/v2.0.txt
index 4ca22f4d261790d14b618b49bacea7afc6fcb6b3..ca6e4277ed84d477e091c4fd90e8444722f058e9 100644
--- a/CHANGES/v2.0.txt
+++ b/CHANGES/v2.0.txt
@@ -17,6 +17,8 @@ In addition, it is now much easier to contribute new functionality to the code b
 - A modular structure 
 - Developer and user documentation 
 
-After release, we will document here fixes and additions on the 2.0.x series.
+Version 2.0.1:
+- Several small fixes in documentation and log file
+- Added message when "plumed simpled" is used on a non-existing file
 
 */
diff --git a/src/cltools/SimpleMD.cpp b/src/cltools/SimpleMD.cpp
index 62fb7f9807ac8cc91b206fbb1d86f0c556ab6d5d..22413465654f563cd324131401e8fa10f90ea2f6 100644
--- a/src/cltools/SimpleMD.cpp
+++ b/src/cltools/SimpleMD.cpp
@@ -190,6 +190,10 @@ read_input(double& temperature,
 void read_natoms(const string & inputfile,int & natoms){
 // read the number of atoms in file "input.xyz"
   FILE* fp=fopen(inputfile.c_str(),"r");
+  if(!fp){
+    fprintf(stderr,"ERROR: file %s not found\n",inputfile.c_str());
+    exit(1);
+  }
   fscanf(fp,"%1000d",&natoms);
   fclose(fp);
 }
@@ -198,6 +202,10 @@ void read_positions(const string& inputfile,int natoms,vector<Vector>& positions
 // read positions and cell from a file called inputfile
 // natoms (input variable) and number of atoms in the file should be consistent
   FILE* fp=fopen(inputfile.c_str(),"r");
+  if(!fp){
+    fprintf(stderr,"ERROR: file %s not found\n",inputfile.c_str());
+    exit(1);
+  }
   char buffer[256];
   char atomname[256];
   fgets(buffer,256,fp);
diff --git a/src/core/CLTool.cpp b/src/core/CLTool.cpp
index 30e2d776c26cab84f97ed2ca4e545d7a7a6e3e34..1b871643d649fd651795a7a36b8d0170cb8b6e3e 100644
--- a/src/core/CLTool.cpp
+++ b/src/core/CLTool.cpp
@@ -157,7 +157,13 @@ bool CLTool::readInputFile( int argc, char**argv, FILE* in, FILE*out ){
   }
 
   FILE* mystdin=in;
-  if(argc==2) mystdin=fopen(argv[1],"r");
+  if(argc==2){
+    mystdin=fopen(argv[1],"r");
+    if(!mystdin){
+      fprintf(stderr,"ERROR: cannot open file %s\n",argv[1]);
+      return false;
+    }
+  }
 
   char buffer[256]; std::string line; line.resize(256);
   while(fgets(buffer,256,mystdin)){