[OnePlus 3T ROMs, Kernels, Recoveries, & Other Deve] myfreexp:
Well, but then it's not "the same", right...?

Uh, even more detailed? I was afraid that I might have been too detailed already. Most people are lazy in reading lengthy posts and dealing with details nowadays. If you're different, that's most welcome and appreciated.

It's not the commands that are the issue (nonetheless I can and will post their output later on in a follow-up-post), as flashing of TWRP appears to work - I mentioned that I'm seeing a TWRP intro/splash screen forever in one case, and a command such as "fastboot reboot" doesn't have any "output" other than a reboot. But anything from then on doesn't work (as described). Either I'm seeing the TWRP splash screen forever (after "fastboot boot twrp.img"), or I'm thrown back into stock recovery (after "fastboot reboot").

The reason of the latter may probably be found => here, at least this is my impression (I did quote that previously):

What I do not understand: According to the headline and the URL, this is a page specific for the OP3T - why should I use Google "to find the proper key combo to enter recovery"? Such things are confusing me. Plus that I don't know how (and why?) to enter a command line "fastboot reboot" and press a key combo at the same time... :confused: The key combo does reboot the phone already, what's the use of the command line then (or vice versa)?

Anyway, none of these commands do bring me "back to the system", as you said. I need to press the power button for a while instead to boot into OOS 4.0.1 again.

Sure, otherwise I'd have mentioned that.

The bootloader is clearly stating DEVICE STATE - unlocked and I'm getting this "untrusted" warning upon each reboot. How much more than this can the device be unlocked...?

I did not wipe anything upon installing TWRP, as neither the instruction in post #1 of this thread nor on this page did tell me to do so (if you search for "wipe" in both texts, you'll only get matches for "swipe"). Even worse, I didn't have the slightest chance to wipe anything, as I did never made it into TWRP past the splash screen.

I did wipe everything, though, when I was following => this instruction from OnePlus before. But this was more an unsuccessful desperate attempt, not really knowing if it's required and helpful or not.

Why should I try a different version? As far as I understood from this thread, 3.0.3-1-beta1 is the one and only to use when on OOS 4.0.x, as previous versions won't work anyway (in terms of encryption/password issues), right?

I have found 3.0.3-1-beta1 in => this thread and downloaded it from => this source.

There is no MD5 checksum given. But as often I download it, it's always binary identical (x-checked it with fc /b). So it's quite unlikely that a failed download may be the reason, wouldn't you agree?

Just to let you know: I may be a complete idiot in terms of Android phones, but otherwise I'm pretty familiar with PC stuff since the early days of DOS 3.x, am a "retired developer" as well (maintainer of a freeware software project written in Borland Pascal). I know that this is outdated stuff, I'm just telling you this so that you know that my knowledge is slightly above zero and that I'm familar with MS command line stuff. My knowledge of Linux is close to zero, though, but OTOH I have already patched some existing PHP code on our mail and web server (by just looking at the code).

The error is that the phone doesn't react as predicted here and elsewhere, details see => my post. The only output that I could post additionally is the result of the flash command. But as TWRP did install in the first place obviously, I didn't see a reason for it. But as I said, I'll post it anyway later on.

I did not doublecheck them, I checked them even ten or more times. Everybody was telling me that as long as ADB and Fastboot are working, everything should be fine.

Generally I'm also extremely concerned about driver issues, see for instance => this post in the OnePlus forum. But nobody did respond in detail so far.

Sure. But I don't have the chance.

Well, as you can see I'm from Düsseldorf, that's not just around the corner, but at least still in NRW. So if you're willing to help (which I would appreciate most), then we could surely meet personally, if all other ways (PM, TeamViewer etc.) might fail.

I'm using the phone also for business purposes , so it's quite important to me to get this solved pretty soon.