[WETEK Play 1] Update to v9.0.0 not possible: "missing (target) kernel.img"

I updated my WETEK-Play from LE to 8.95.1. without any problem.

Then the update to 8.95.2 and the following Beta Versions were not possible: In each case I got the message "missing (target) kernel.img or SYSTEM".

Now I tried to update to 9.0.0 and I get the same message

What did I do: I tried to update in three different ways:

1. directly in LE

2. Download of the LibreELEC-WeTek_Play.arm-9.0.0.tar - File to the PC, then copy it to the update-folder on the WETEK

3. same as 2., but unpacked the img before copying to the update folder of the WETEK.

Same result in all three ways: No update. Instead the message "missing (target) kernel.img or SYSTEM" and then starting the v8.95.1.

Can anyone tell me how to update the WETEK to 9.0.0.?

Thanks in advance

Thank you for the tip. I tied the shell script and it really worked. The update is ok now - I am at 9.0.0 now.

But - this cannot be the real solution? There must be a bug somewhere.

Does anyone now if it is possible to upgrade to 9.0.0. the "legal" way?