I have successfully migrated from joomla 3.10.11 to 4.2.5
Before that I have
helixultimate_template_v2.0.11.zip
and
helix_ultimate_plugin_pkg_2.0.11.zip
installed
The template worked already on Joomla 3
Have also already adjusted the module position.
Cassiopeia - Default is working, except wrong module positions
On Joomla 3 the page ran with template Joomspirit 140
Before migration I uninstalled all site templates except Helix and Beez.
Please have a look what to do.
https://2023.eifelverein-marmagen.de/