I am working also with a German version.
However, after migrating a Jira instance from 6.4.11 to Jira Software 7.12 I foundan issuetype named "EPOS". This one is the equivalent to the issuetype "Epic". In consequence this means that all related customfields like epic name or epic link are name "Epos Name" and "Epos-Verknüpfung".
Because Jira Software and many addons are speaking of Epics all over (also in a German Version) I like to change the name of the issuetype. However I can change the name of the issuetype but the customfields are locked and I cannot change their names.
Is there a way to change these customfields. Otherwiese it would be quite confusing for users.
Best regards and thanks for the help,
Simon
P.S.
I just recognized that if I change the name of issuetype "Epos" to "Epic" the epic panel of the boards are empty.
Is there a solution to this issue?