Error in Edit View when replacing a file

[vivien-lindemann-gfz]

In Edit View it is not possible to replace a file.

I always get this error message:
Argument 1 passed to In2code \ Powermail \ Domain \ Model \ File :: setField () must be an instance of In2code \ Powermail \ Domain \ Model \ Field, null given, called in /[..]/typo3conf/ext/powermail/Classes/Domain/Factory/FileFactory.php on line 146

My search showed that
https://github.com/einpraegsam/powermail/blob/329c50eba1f0a88e787c2a24b3c985bd913040e5/Classes/Domain/Factory/FileFactory.php#L165
probably causes the problem,
because tx_powermail_pi1 is passed as key in
https://github.com/einpraegsam/powermail/blob/329c50eba1f0a88e787c2a24b3c985bd913040e5/Classes/Utility/FrontendUtility.php#L272

But in edit view tx_powermail_pi2 would be needed.

How can the problem be solved?

TYPO3 10.4.12
Powermail 8.3.0