5 FORMAT(A80)

The soft read from file 10 (metal.dat) and after that jump to label 800 when reading data presented in file was completed. It is OK. It is right work. The question is why the soft does not stop to "entering requested metal" after label 800. I will send you full code file to support@approximatrix.com.

              READ(10,5,ERR=800) WORD80     ! skip line of:123345....

fails and the program correctly jumps to label 800.  I don't know why it fails, though, without knowing what the FORMAT statement at label 5 is.  Could you provide a bit more?

  CHARACTER (len=80) WORD80
      CHARACTER(len=80) MTLNAME
      CHARACTER(len=16) WORD16
      CHARACTER(len=21) WORD21
      CHARACTER(len=39) WORD39
     
      CHARACTER(len=1) YN
C
      DIMENSION   TMPDAT(15), FTUDAT(15),FTYDAT(15),
     +            CRPDAT(15)
C
      OPEN(UNIT = 10, FILE = 'METAL.DAT', STATUS = 'OLD')

C       --------------------------------------------------------------
C        ---request for metal number from data,and preparing a list --
C         --------- of metals for the user ----------------------------
C
      WRITE(*,1)
      REWIND 10
              DO ILINE = 1, 10              ! read 10 lines of comments
                 READ(10,5) WORD80
              END DO
  200 CONTINUE             
              READ(10,5,ERR=800) WORD80     ! skip line of:123345....
              READ(10,5) WORD80
              WRITE(*,5) WORD80             ! print metals name
                 DO JLINE = 1 , 28          ! skip remaining lines
                    READ(10,5) WORD80
                 END DO
              GO TO 200         
C     
  800 CONTINUE 
C     ------------- entering  requested metal ------------------
      WRITE(*,2)
      READ(*,*) NMT
C             
C      -------reading data for request metal--

  2 FORMAT(/,2X,'Select the sequential number of metal = ',/)

It appears, though, that the backslash is merely attempting to stop the WRITE statements from advancing to a new line (technically it stops "advancing a record," which is a line in this case, I'm guessing).  You can change this easily to standards-compliant Fortran, though it will be a modern Fortran standard.  First, remove the backslashes from all the FORMAT statements:

     1 FORMAT(2X,'FLUID NUMBER=')

Next, you'll need to modify the WRITE statements as well with the modern, standards-compliant change:

       WRITE(*, 1, ADVANCE='NO')

That's the quickest way to fix this.  Luckily, it appears you only have a handful of places that needs changes.

If you don't care about everything being on the same line, though, you can always just delete the backslashes and take no other action.

If you do need to send code, you can always contact me at support@approximatrix.com.

==============================================================================
Generating Makefile... Okay
==============================================================================
Compiling .\Refrig.for
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.\Refrig.for:117:33:

  117 |     1 FORMAT(2X,'FLUID NUMBER=',\)
      |                                 1
Error: Unexpected element '\' in format string at (1)
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.\Refrig.for:118:36:

  118 |     2 FORMAT(2X,'TEMPERATURE,[C]=',\)
      |                                    1
Error: Unexpected element '\' in format string at (1)
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.\Refrig.for:122:28:

  122 |     5 FORMAT(2X,'FLUID - ',\)
      |                            1
Error: Unexpected element '\' in format string at (1)
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.\Refrig.for:135:72:

  135 |       PAUSE
      |                                                                        1
Warning: Deleted feature: PAUSE statement at (1)
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.\Refrig.for:24:72:

   24 |       WRITE(*,1)
      |                                                                        1
Error: FORMAT label 1 at (1) not defined
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.\Refrig.for:26:72:

   26 |       WRITE(*,2)
      |                                                                        1
Error: FORMAT label 2 at (1) not defined
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.\Refrig.for:113:72:

  113 |       WRITE(*,5)
      |                                                                        1
Error: FORMAT label 5 at (1) not defined
Error: Last command making (build\Refrig.o) returned a bad status
Error: Make execution terminated

* Failed *