These lines of code cause the segfault and core dump:

my $button1 = $mw->Photo(-data => &encoded_but1, -format => 'gif');
my $button2 = $mw->Photo(-data => &encoded_but2, -format => 'gif');
my $button3 = $mw->Photo(-data => &encoded_but_exit1, -format => 'gif'
+);
my $button4 = $mw->Photo(-data => &encoded_but_exit2, -format => 'gif'
+);

my $but1 = $c->createImage(40, 400, -image => $button1, -anchor => 'nw
+', -tags => ['but1']);

$c->bind( $but1, '<Enter>', sub {$c->itemconfigure( $but1, -image => $
+button2); });
$c->bind( $but1, '<Leave>', sub {$c->itemconfigure( $but1, -image => $
+button1); });
$c->bind( $but1, '<ButtonPress>', sub{ &tabbed; } );

my $but2 = $c->createImage(450, 400, -image => $button3, -anchor => 'n
+w', -tags => ['but2']);

$c->bind( $but2, '<Enter>', sub {$c->itemconfigure( $but2, -image => $
+button4); });
$c->bind( $but2, '<Leave>', sub {$c->itemconfigure( $but2, -image => $
+button3); });
$c->bind( $but2, '<ButtonPress>', sub { 
        &disconnect;
        $mw->fontDelete('info_rus'); $mw->fontDelete('ticks'); $mw->fo
+ntDelete('bar_rus'); $mw->fontDelete('dial_rus');
        exit; });
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These lines of code cause the segfault and core dump:

Awesome, which line exactly?

The next step is to find which line exactly and create a minimal program which reproduces the bug :)

It could be Bug #29640 for Tk: Memory Issus with TK::Photo and -data option

I noticed that the error occurs after activating the Quit button (выход), but not if the application is closed from the frame's close button on the title bar.

I noticed that the error occurs after activating the Quit button (выход), but not if the application is closed from the frame's close button on the title bar.

Try calling destroy on your mainwindow instead of perl function exit, or maybe use Tk::exit