Extract the zip File from
this post. You can flash the .img through TWRP as an Image file. Or You can use odin/heimdall and flash the .tar file to Update TWRP.
I am using the lates version and everything works fine. It could also be possible that you ROM zip file is corrupted and you may need to redownload it.
Edit:
You are using the wrong file to flash you have to use herholte (Normal S7) or hero2lte (S7 edge).
For example:
PixelExperience_Plus_
herolte-13.0-20221119-1641-UNOFFICIAL.zip (
Normal S7)
PixelExperience_Plus_
hero2lte-13.0-20221119-1335-UNOFFICIAL.zip (
S7 Edge)