Custom pxemenu.txt and UEFI error

Hello,
I have a changed the pxemenu.txt file since ZCM 10.X.
Now I copied it to the new location for uefi boot to /srv/tftp/efi/x86_64.
the syntax is changed to the new version2 like in the origin pxemenu.txt in this folder.
Is there a size limitation or will be a md5 checksum done?
The filesize is 2868 byte.
The menu doesn´t appear and I get an error: ASSERT_EFI_ERROR (Status = Invalid Parameter).
ZCM is on 11.2.4 patchlevel.
Any help?

regards
Andy