System Console with TK support

Hi,

I have got a question about the TK support of the System Console. According to this page:

https://www.altera.com/support/support-resources/knowledge-base/solutions/rd01212014_911.html

I can run a simple GUI with the System Console. The minimal Example on the page works once, so when I run it in my script I get this output:

% source my_script.tcl
error: invalid command name "???"
    while executing
"??? button .b2 -text {World} -underline 0"
    (file "my_script.tcl" line 5)
    invoked from within
"source my_script.tcl"

Ok there might be something wrong with the text, but that is not the problem at the moment.

When I try to run it again, suddenly something is wrong:

% source my_script.tcl
error: can't invoke "button" command:  application has been destroyed
    while executing
"button .b1 -text {Hello} -underline 0"
    (file "my_script.tcl" line 3)
    invoked from within
"source my_script.tcl"

I would be very happy, if someone could help me with that.

Best Regards,

Philipp