Passing a string in XC8

Hi,
I'm using MPLAB X IDE v1.63,  XC8 v2.31 and a Pickit 3 to write to a PIC18F67k40 on a MIKROE Click 2.
 
For some reason I am unable to pass a fixed string (const char*) to a function
 
const char buff1[]="String1";     // string in Program memory
 
void WriteStr(const char *str)     // function using the string
{...process str ...}
 
using
        WriteStr("String0"); 
or
        WriteStr(buff); 
 
I can see the text in program memory (at E01) and the address is passed to the function, but I believe that this is RAM address and has not been converted for Program Memory.  The compiler seems to be using the right address but looking in the wrong memory block. I believe the compiler should automatically use the correct address as XC8 does not seem to have a ROM type/command like XC16. I have tried several variant of this code with arrays, pointers, statics , const and normal char without success. I have used similar code on other systems, so I am thinking that it is more likely to be the compiler options or development environment.
 
Thanks
Paul

+1
There's some more background in this thread: https://www.microchip.com/forums/m969418.aspx
 

If the array is defined inside a function rather than global or static, then it IS in RAM. can't tell from the isolated snippet you have posted.

ric
There is a missing post in this thread by "OscarTheGrouch".
I assume it contained one of the Firewall trigger words.

LOL, I triggered something? Is the FBI going to visit? ;)