diff --git a/src/shared/read_parameter_file.F90 b/src/shared/read_parameter_file.F90
index 3ededff71..9e65d0274 100644
--- a/src/shared/read_parameter_file.F90
+++ b/src/shared/read_parameter_file.F90
@@ -1395,8 +1395,8 @@ subroutine read_parameter_file_only()
 
   if (some_parameters_missing_from_Par_file) then
     write(*,*)
-    write(*,*) 'All the above parameters are missing from your Par_file.'
-    write(*,*) 'Please cut and paste them somewhere in your Par_file (any place is fine), change their values if needed'
+    write(*,*) 'All the above parameters are either in a wrong number format or missing from your Par_file.'
+    write(*,*) 'Please correct or cut&paste them somewhere in your Par_file (any place is fine), change their values if needed'
     write(*,*) '(the above values are just default values), and restart your run.'
     write(*,*)
     call stop_the_code('Error: some parameters are missing in your Par_file, it is incomplete or in an older format, &
diff --git a/src/shared/read_source_file.f90 b/src/shared/read_source_file.f90
index 674b7d316..c91e0e62c 100644
--- a/src/shared/read_source_file.f90
+++ b/src/shared/read_source_file.f90
@@ -52,6 +52,7 @@ subroutine read_source_file(NSOURCES,BROADCAST_AFTER_READ)
   character(len=256) string_read
   character(len=MAX_STRING_LEN) :: source_filename,path_to_add
   integer, parameter :: IIN_SOURCE = 22
+  logical :: stf_exists
 
   ! user output
   if (myrank == 0) then
@@ -315,6 +316,17 @@ subroutine read_source_file(NSOURCES,BROADCAST_AFTER_READ)
       write(IMAIN,*) '  Multiplying factor  = ',factor(i_source)
       write(IMAIN,*)
 
+      ! check if external stf file exists
+      if (time_function_type(i_source) == 8) then
+        inquire(file=trim(name_of_source_file(i_source)),exist=stf_exists)
+        if (.not. stf_exists) then
+          write(*,*) ''
+          write(*,*) 'Error external source time function file: ',trim(name_of_source_file(i_source)),' not found.'
+          write(*,*) ''
+          call stop_the_code('Error reading SOURCE file: could not find specified external source time function file')
+        endif
+      endif
+
     enddo ! do i_source= 1,NSOURCES
     close(IIN_SOURCE)
 
diff --git a/src/shared/read_value_parameters.f90 b/src/shared/read_value_parameters.f90
index b07e4b5a0..8721919eb 100644
--- a/src/shared/read_value_parameters.f90
+++ b/src/shared/read_value_parameters.f90
@@ -197,7 +197,7 @@ subroutine read_value_integer_p(value_to_read, name)
 
   call param_read(string_read, len(string_read), name, len(name), ierr)
   if (ierr /= 0) return
-  read(string_read,*) value_to_read
+  read(string_read,*,iostat=ierr) value_to_read
 
   end subroutine read_value_integer_p
 
@@ -217,7 +217,7 @@ subroutine read_value_double_precision_p(value_to_read, name)
 
   call param_read(string_read, len(string_read), name, len(name), ierr)
   if (ierr /= 0) return
-  read(string_read,*) value_to_read
+  read(string_read,*,iostat=ierr) value_to_read
 
   end subroutine read_value_double_precision_p
 
@@ -237,7 +237,7 @@ subroutine read_value_logical_p(value_to_read, name)
 
   call param_read(string_read, len(string_read), name, len(name), ierr)
   if (ierr /= 0) return
-  read(string_read,*) value_to_read
+  read(string_read,*,iostat=ierr) value_to_read
 
   end subroutine read_value_logical_p
 
@@ -277,7 +277,7 @@ subroutine read_value_integer_next_p(value_to_read, name)
 
   call param_read_nextparam(string_read, len(string_read), name, len(name), ierr)
   if (ierr /= 0) return
-  read(string_read,*) value_to_read
+  read(string_read,*,iostat=ierr) value_to_read
 
   end subroutine read_value_integer_next_p
 
@@ -297,7 +297,7 @@ subroutine read_value_double_prec_next_p(value_to_read, name)
 
   call param_read_nextparam(string_read, len(string_read), name, len(name), ierr)
   if (ierr /= 0) return
-  read(string_read,*) value_to_read
+  read(string_read,*,iostat=ierr) value_to_read
 
   end subroutine read_value_double_prec_next_p
 
@@ -317,7 +317,7 @@ subroutine read_value_logical_next_p(value_to_read, name)
 
   call param_read_nextparam(string_read, len(string_read), name, len(name), ierr)
   if (ierr /= 0) return
-  read(string_read,*) value_to_read
+  read(string_read,*,iostat=ierr) value_to_read
 
   end subroutine read_value_logical_next_p
 
diff --git a/src/specfem2D/setup_sources_receivers.F90 b/src/specfem2D/setup_sources_receivers.F90
index b4f083d22..ce0cb3a96 100644
--- a/src/specfem2D/setup_sources_receivers.F90
+++ b/src/specfem2D/setup_sources_receivers.F90
@@ -140,10 +140,12 @@ subroutine setup_sources()
 
         ! user output
         if (not_in_mesh_domain) then
-          write(IMAIN,*) 'Source ',i
-          write(IMAIN,*) '  Position (x,z) of the source = ',x_source(i),z_source(i)
-          write(IMAIN,*) 'Invalid position, mesh dimensions are: xmin/max = ',xmin,xmax,'zmin/zmax',zmin,zmax
-          write(IMAIN,*) 'Please fix source location, exiting...'
+          write(IMAIN,*) 'Error: Source ',i
+          write(IMAIN,*) '       Position (x,z) of the source = ',x_source(i),z_source(i)
+          write(IMAIN,*)
+          write(IMAIN,*) '       Invalid position, mesh dimensions are: xmin/max = ',xmin,xmax,'zmin/zmax',zmin,zmax
+          write(IMAIN,*) '       Please fix source location, exiting...'
+          write(IMAIN,*)
           if (x_source(i) < xmin) call stop_the_code('Error: at least one source has x < xmin of the mesh')
           if (x_source(i) > xmax) call stop_the_code('Error: at least one source has x > xmax of the mesh')
           if (z_source(i) < zmin) call stop_the_code('Error: at least one source has z < zmin of the mesh')