See Ray Smith's notes in tess4/TrainingTesseract 4.00, specifically the section on errors.
Normal C++ programs like those which are built for tesseract automatically set the locale "C".
There can be different locale settings if the tesseract library is used in other software.
A wrong locale can cause wrong results from sscanf which is used at different places in the tesseract code, so make sure that we have the right locale settings and fail if that is not the case.
!strcmp(locale, "C"):Error:Assert failed:in file baseapi.cpp, line 192
You have to find out whether "C" works with your code or you must restore the original locale after calling the Tesseract API.