ESP32-Cam won't boot with SD-Card plugged in

[TimFES]

Hello,

I bought a ESP32-Cam to digitalize my water meter. Therefore I bought a manual that tells me the exact steps that I have to do. I have connected my ESP32-Cam with a FTDI-Controller to my PC and just use the command line of a Linux VM.
First I should delete everything from the ESP32's flash (with the command erase-flash). Next I should install the bootloader.bin, the partitions.bin and the firmware.bin on the flash of the ESP32-Cam. Therefore I of course used the bootloader-mode ( GPIO0 connected to GND). Everthing works fine and I finally should put some data like the wlan.ini (data to connect to the wifi) on SD-Card that has the format "FAT32". Now I can boot the ESP32-Cam but when the SD-Card is plugged in it won't do anything (no LEDs are flashing). As soon as I remove the SD-Card it boots up I think because the LEDs start flashing but it can't connect to the wifi because the wlan.ini is missing.
So basically the ESP32-Cam won't do anything when a SD-Card is plugged in. I tried different SD-Card sizes (never more then 16GB capacity) and also different ESP32-Cams but still no succes.

Thanks for responding in advance.

Greetings
Tim Finmans