Hello @jae, thank you for posting, we weren’t aware of these changes. Are you able to share a sample IOS18 HIEF file you’d like to be able to read into FME Form and logfile of the failed read? Do you see any errors in the logfile? If you are unable to share these things publicly, please consider submitting a support case. 

I know there was a workaround for reading HEIC files with 24 bit depth (support up to 16 right now) by changing the image file extension to JPEG and using the JPEG Reader. You could try this on a copy of a photo to see if its applicable here temporarily / until we sort out a solution. I realize this may not be ideal, apologies. Happy to help, Kailin.