Midnight Commander still have a problem with pseudographics even in version 4.8.20.
Trouble is related to utf8 encoding in /etc/mc/skins/default.ini file.
And I dont know why.
But I use little hack with this file. I just replace utf8-encoded pseudographics with latin characters (-|+*).
Looks good enouth.
Something like this (only [Lines] section have to be changed):
[Lines]
horiz = -
vert = |
lefttop = *
righttop = *
leftbottom = *
rightbottom = *
topmiddle = *
bottommiddle = *
leftmiddle = *
rightmiddle = *
cross = +
dhoriz = -
dvert = |
dlefttop = *
drighttop = *
dleftbottom = *
drightbottom = *
dtopmiddle = *
dbottommiddle = *
dleftmiddle = *
drightmiddle = *