The reason why the caches will not clear is that you are not decrypting your data. TWRP 3.4.0 cannot decrypt and so the errors come up.
You will need to boot (not flash) with a different TWRP that can decrypt your data.
The TWRP that I use to install, I boot (not flash) each time with:
Download: 3.4.2b-0623 TWRP
fastboot boot [TWRP-3.4.2b-0623-umi.img]
(There will be a delay before it loads up, and a further delay before you can input your pattern.)
This will only decrypt with a pattern access. So you will need to make sure that you unlock your phone with a pattern in order to access it.
You will then be able to install from your phone, and then clear the Dalvik and cache, and also delete the /data/system/package_cache folder.
thank you, but this is all too complicated for me. so i can't go back to 20.11.18 with this twrp version ???