How can i find out what causes "Not initialised string" ?

 
hmm may be a build 201 bug appearing when passing "" to a function . With EMPTY instead of "" there seem to be no error.
 
Ok it was my error by passing by reference a non initialized string (I never wanted to do anything with initial value, just used that string to get some values inside from the called function). It's just a warning for the programmer, it shouldn't fill logs. Compilers, starting from the last versions of C++ started to show warnings along with their places. This one appears as a runtime warning and fill logs without even telling the programmer that exists (if you don't look on Experts tab). It would be a nasty surprise for someone running a "defective" EA on a rental server with a predetermined disk space at disposal.
 
Sample of uninitizalized string:
string some_string;
Sample of initialized string:
string some_string="abc123";
or
string some_string;
some_string="abc123";
Reason: