Here’s a guide to really install from scratch … just follow steps 1 to 4 (or step 4 only if you can still boot into TWRP by keeping Volume + pressed while starting or rebooting the phone) and then try installing /e/ again …
Hi! Thank you for helping out. The permission problem was solved by changing computer and reinstall platform-tools. After downgrading to twrp 3.2.3.0 (as recomended in Link for reinstalling fairphone os) i again first tried flashing e/os. And this time it worked perfectly.
Just a note for others perhaps reading along … The mentioned guide doesn’t recommend a specific TWRP version, it only says to download the current one. TWRP 3.2.3-0 is shown in the screenshots simply because it was the current version when the initial TWRP screenshots in the guide were made .
That being said, 3.2.3-0 has proven to be a reliable and stable workhorse on the Fairphone 2, I’m not a big fan of the 3.3 versions, which had their quirks, and I can’t say much about the relatively new 3.4.0-0.