Hi Oachkatze,
I assume, that the external flash of the ACTRON board is used in you project, however the external flash loader file for the STM32 ST-LINK Utility is missing.
Please copy the external loader file 'ACTRON_LIZARD_MT25QL512_ST_V2.1.stldr' from the folder 'STM32F469-LIZARD\ThirdParty\ACTRON\ExternalLoader' of the STM32F469-LIZARD build environment to the 'ExternalLoader' folder of your STM32 ST-LINK Utility installation (default: C:\Program Files (x86)\STMicroelectronics\STM32 ST-LINK Utility\ST-LINK Utility\ExternalLoader).
Regards,
Martin