Sorry for my late reply, I'm rather busy at the moment. Anyhow, below is the error message I receive after inluding Devel::SimpleTrace. I'm not able to judge whether this makes things more clear or not but hopefully you are.

Chart type 'External' not supported in add_chart()
    at Spreadsheet::WriteExcel::Chart::factory(unknown source)
    at Spreadsheet::WriteExcel::Workbook::add_chart_ext(Spreadsheet/Wr
+iteExcel/Workbook.pm:560)
    at analyse_step::generate_report_excel(cavaexecscript/analyse_step
+.pm:679)
    at main::save_report(cavaexecscript/csct.pl:1011)
    at main::__ANON__(cavaexecscript/csct.pl:376)
    at <eval>(Tkx.pm:343)
    at Tkx::i::DoOneEvent(Tkx.pm:343)
    at Tkx::MainLoop(Tkx.pm:56)
    at <eval>(cavaexecscript/csct.pl:707)
    at Cava::Pack::Code::_run_packaged_script(<Packaged Modules>/Appli
+cation::Loader:1456)
    at Cava::Pack::Code::_run_doscript(<Packaged Modules>/Application:
+:Loader:1483)
    at main::(<Packaged Modules>/Application::Loader:1523)

Chart type 'External' not supported in add_chart()
    at Spreadsheet::WriteExcel::Chart::factory(unknown source)
    at Spreadsheet::WriteExcel::Workbook::add_chart_ext(Spreadsheet/Wr
+iteExcel/Workbook.pm:560)
    at analyse_step::generate_report_excel(cavaexecscript/analyse_step
+.pm:679)
    at main::save_report(cavaexecscript/csct.pl:1011)
    at main::__ANON__(cavaexecscript/csct.pl:376)
    at <eval>(Tkx.pm:343)
    at Tkx::i::DoOneEvent(Tkx.pm:343)
    at Tkx::MainLoop(Tkx.pm:56)
    at <eval>(cavaexecscript/csct.pl:707)
    at Cava::Pack::Code::_run_packaged_script(<Packaged Modules>/Appli
+cation::Loader:1456)
    at Cava::Pack::Code::_run_doscript(<Packaged Modules>/Application:
+:Loader:1483)
    at main::(<Packaged Modules>/Application::Loader:1523)

    while executing
"::perl::CODE(0x30239ec)"
    invoked from within
".n.f3.l3.b2 invoke "
    invoked from within
".n.f3.l3.b2 instate {pressed !disabled} { .n.f3.l3.b2 state !pressed;
+ .n.f3.l3.b2 invoke } "
    (command bound to event)
[download]

I would very much appreciate if you have any ideas on how to fix this issue! Thanks!

I'm not able to judge whether this makes things more clear or not but hopefully you are.

It doesn't help at all. Do you have packed Spreadsheet/WriteExcel/Chart/External.pm ?

I have forced Cava to include SpredSheet::WriteExcel and I guess that will do it?

UPDATE: Some more details. What seems to be the problem is when I'm adding a chart in a separate worksheet. I have several other charts that I'm using in a worksheet also containing some other data and that works fine. The difference is that to add these charts the command embed_chart is used while to add the chart in the separate worksheet (which is not working) the command add_chart_ext is used.

To generate the bin-files used by these functions, the chartex function is being used and all seems to work well during that process.

I guess the thing that is the most puzzling is that it all works in an unpacked version but when packaged by Cava, everything works but the add_chart_ext command which produces an error.

Any ides around how to make this work are highly appreciated!