Reading and flashing went like a breeze. Fortunately the chip was not encrypted. After I was sure that I could read from the PIC I changed the Byte for minimum tuning power.?
Flash file (hex tailor file) is it on your computer or on the chip? If the chip is encrypted, it cannot read the codes. You need to load flash files from your computer.
Thanks to all the comments - they helped. The connection between atu and pickit as it was shown in IK3SSGs video didn't work for me - after changing the connection the PIC was immediately detected and I cpuld read everything from the device.