postinstall initialpermission is not working in FLEXIcontent 3.0.11

Hi

since 8 years i use FLEXIcontent 3.0.0 at a intranet webpage.
Now i do a update to FLEXIcontent 3.0.11 because a needed update to php 7.4.

I know my old Version of FLEXIcontent 3.0.11 but i need a hotfix to work again with the content and to update to the next newer flexcontent Versions.

On postinstall the initialpermission is not working anymore.

LOG:
Deleted actions: Array ( )
Added actions: Array ( [0] => core.admin [1] => core.manage [2] => core.create [3] => core.edit [4] => core.edit.own [5] => core.edit.state )
Component DB Rule Count 0
Component File Rule Count 52
PASSED comp_section: && category_section:1 && article_section:1 && field_section:1 && type_section:1

I can stop the postinstall in
/administrator/components/com_flexicontent/models/flexicontent.php
in function checkInitialPermission() {
return true

but i need a real fix for that issue.

Any suggestions?
What are the right steps to update from FLEXIcontent 3.0.11 to Flexicontent 4.2.1 ?

Sorry i am in vacation for 3 weeks.