Well, I tried to spare you from the long answer, but here it goes:
To arrive at the I-don't-know-if-it-is-correct solution of changing the value of MAXKEYWORD I searched the sources of TELEMAC for the error message "ADRESS GREATER THAN NMAX". This message is triggered by damoc. or classe.f when some variable has a value bigger than NMAX:
IF (ADDES.GT. NMAX) GO TO 1515
1515 WRITE(LU,*)'ADRESSE SUPERIEURE A NMAX = ',NMAX
CALL PLANTE(1)
Then I looked at the call tree of these subroutines looking for the variable NMAX, and found out that damocle.f is called with NMAX from lecdon_telemac3d.f, where this variable is called MAXKEYWORD.
CALL DAMOCLE( ADRESS , DIMEN , MAXKEYWORD , DOC , LNG , LU ,
& MOTINT , MOTREA , MOTLOG , MOTCAR , MOTCLE ,
& TROUVE , ID_DICO, ID_CAS , .FALSE. , FILE_DESC )
Finally, I searched for the declaration of MAXKEYWORD and the only place I found is in the module declarations_special.f, which is then used by lecdon_telemac3d.f.
INTEGER, PARAMETER :: MAXKEYWORD = 300
TL;DR: If you increase the value of MAXKEYWORD enough that error will not be triggered anymore.
BUT I don't know what is the purpose of this limit in the code, so maybe you'll change it and the program will crash somewhere else. But until someone who knows the purpose of MAXKEYWORD in the code answers you, the only way of finding out if it works is changing it and running your simulation.
And unfortunately, if you cant upload the simulation files, there's no way I can help you further.
Best regards,
Phelype