Yes. I made following changes:
-free(msg);
+Safefree(msg);

-char *thread_arg = malloc((strlen(msg)+1)*sizeof(char));
+char *thread_arg;
+Newx(thread_arg, strlen(msg)+1, char);

[download]
But this didn't help. Still crashes

In reply to Re^4: XS: free() outside of the main thread causes crash on Windows by OlegG
in thread XS: free() outside of the main thread causes crash on Windows by OlegG

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