"forrtl: severe (174): SIGSEGV, segmentation fault occurred" after adding or removing write-type commands

Hi, 

I'm compiling an ice sheet model using IFORT. If I add or remove some very simple write-type code, I have the following error message 

forrtl: severe (174): SIGSEGV, segmentation fault occurred
Image              PC                Routine            Line        Source             
libintlc.so.5      00007F4D9B0E3961  Unknown               Unknown  Unknown
libintlc.so.5      00007F4D9B0E20B7  Unknown               Unknown  Unknown
libifcore.so.5     00007F4D9CAA41D2  Unknown               Unknown  Unknown
libifcore.so.5     00007F4D9CAA4026  Unknown               Unknown  Unknown
libifcore.so.5     00007F4D9CA10E0C  Unknown               Unknown  Unknown
libifcore.so.5     00007F4D9CA21BF8  Unknown               Unknown  Unknown
libpthread.so.0    00007F4D9AEC9340  Unknown               Unknown  Unknown
sheetshelf.exe     000000000AA54D90  Unknown               Unknown  Unknown

Here is an example  of a write command I removed 

#       do iu = ioterm, iuout1d, iuout1d-ioterm
#       write (iu,'(a,i3,2(a,f10.4))')
#     *    'itera=',itera, ' delmaxa=',delmaxa,' delcrita=',delcrita
#       enddo

and here is an example of a write command I added 

#       write(*,*)'crhu-schoof',crhu(iau,j),iau,j

I checked many times that there are no errors re the variables I want to be written, so I really can't understand why this happens. Do you have any hint how to understand more of this error? 

Thank you,

Michele