This is what the HTK Book says:

+7036: Duplicate macro
Attempted to create a macro with the same name as one already present.
Choose a dierent name.

What is in your macros file?

~o
<STREAMINFO> 1 25
<VECSIZE> 25<NULLD><MFCC_D_N_Z_0><DIAGC>
~v varFloor1
<Variance> 25
 3.016045e-01 3.645148e-01 2.380220e-01 2.895490e-01 3.008639e-01 4.371657e-01 2.277404e-01 3.007877e-01 3.286861e-01 1.631838e-01 1.774076e-01 1.732238e-01 5.916479e-03 9.587396e-03 7.054548e-03 8.874703e-03 9.015174e-03 1.356081e-02 9.275147e-03 1.059783e-02 1.256262e-02 8.585281e-03 8.685526e-03 7.890525e-03 4.629937e-03

Hum... do you have a duplicate entry in your monophones0 file?

No, HTK outputs the following,

ERROR [+7036]  CreateHMM: multiple use of logical HMM name @
  ERROR [+7060]  InitHMMSet: Error in CreateHMM
  ERROR [+2321]  Initialise: MakeHMMSet failed
 FATAL ERROR - Terminating program HERest

--

Well, I only have one "@" in my "monophones0" file (and one "'@").

>ERROR [+7036]  CreateHMM: multiple use of logical HMM name @

HTK might not like the "@" character as a phone... try a letter or combination of two letters.

Ok, it's fine, the problem is with the single quote before the @ and other phones ...

I just need to modify every files that contains phones

i have the same problem

 ERROR [+7036]  NewMacro: macro or model name ST_ey_2_1 already exists
FATAL ERROR - Terminating program HHEd

what i can do?

>i have the same problem

[...]

>what i can do?

don't use non-standard ASCII characters for your monophones - stick to letter and numbers, no more than 2 characters.