The "missing modules" error means the CHDK build cannot find the primary CHDK binary file (usually named PS.FI2 or similar depending on the boot method) in the root of the SD card. (edit by reyalp: this is wrong, the error means the modules in CHDK/MODULES are not found, if the main binary wasn't found, CHDK wouldn't run)
Ensure your SD card is formatted as FAT32 and has the following in the root directory: (edit by reyalp: Ixus75 can't boot from FAT32)
- The CHDK binary:
PS.FI2 (if using the FI2 boot method) or DISKBOOT.BIN.
The boot flag: If using the DISKBOOT.BIN method, the card must be locked (switch slid down) to enable the boot flag. (edit by reyalp: the "boot flag" refers to the BOOTDISK string in the MBR, not the lock switch)Vers.req: Ensure this file is present if the camera requires it to detect the card, though it is less common on newer ports. (edit by reyalp: this is wrong, vers.req is never required to boot, it's only used for obtaining version information)
Double-check that you downloaded the correct "complete" zip package for your firmware version, not just an update, and extracted all contents to the card. A wrong firmware version build will simply not load, whereas missing files cause this specific error.
