Double Entry of "Multilingual Associations", but had core components before install of this package.

Which sql did you use?

https://github.com/zero-24/joomla-cms/archive/fix_install_sql.zip

Which SQL file / testing data did you try to install.

i installed the fix_install_sql.zip – your Question show i shouldn't.

In the installation prozess you choose a sample data set learning, blog, testing etc. Which did you choose?

i installed it in Joomla3.7-beta1 > Joomla Update. In the Meantime i installed a clean beta1.

I mean this options described here: https://www.ostraining.com/blog/joomla/joomla-3-sample-data/

I had a 3.7beta1 (multilingual, no sample data) and installed fix_install_sql.zip on top.

Yes and this does not fix everything ;) we need a clean install using my package testing all options maybe also multilingual and confirm the backend menu contains all menu entrys.

now i understand …

I have tested this item ✅ successfully on 578dac4

I do test as:
git pull upstream staging
curl https://patch-diff.githubusercontent.com/raw/joomla/joomla-cms/pull/13894.diff | git apply

install each sample data, login as admin and I checked menus on backend, (on frontend I checked only on one sample data)

This patch got tested by @obuisard here: #13905 (comment)