Step to reproduce bug:
1. Create table with non-latin (russian) text in cells.
2. Save it to .txt file.
3. Load this file.
Results of saving:
1. Text in table .txt file correctly saved in UTF-8.
Results of loading:
1. Lots exceptions (attached).
2. Messages on terminal:
/var/tmp/portage/x11-libs/wxGTK-126.96.36.199/work/wxPython-src-188.8.131.52/src/common/unichar.cpp(53): assert "Assert failure" failed in FromHi8bit(): invalid multibyte character
3. Cells with some mismath instead original text.
System: Gentoo Linux with LANG=ru_RU.UTF-8.
Version of Saga: current svn trunk (r1769).
I will attach my workaround in comment, it's ugly, but works for me.