Download installation files not working

I have issues when trying to install openHAB 2.5.2 on Synology NAS.
I get the following Error Meassage:

ERROR:
There was a problem downloading openhab-2.5.2.zip from the download link:
https://bintray.com/openhab/mvn/download_file?file_path=org/openhab/distro/openhab/2.5.2/
Alternatively, download this file manually and place it in the ‘/volume1/public’ shared folder and start installation again.

It seems that bintray.com is not available anymore. Can I download the required file openhab-2.5.2.zip somewhere else?

I don’t think any version that old is available any more since Bintray shut down. Given that the SPK file was created in March of 2020 I’m certain that it’s pointing to the wrong location.The oldest download still available is 2.5.12: Download openHAB | openHAB

I do not want to stay on this old version. I would be happy to go to the latest version.
My problem is that I used to install openHAB on my Synology NAS according to the instruction on Synology DiskStation | openHAB.
The latest version on Releases · openhab/openhab-syno-spk · GitHub is 3.0.0.000 but it has no spk file with it. That is why I wanted to re-install 2.5.2 which is the second latest version.

Maybe somebody can give me a hint how to install (any) version of openHAB on my Synology NAS.
I am already missing it very much after only 2 days…

I think most people use Docker to install on a NAS. But all I really know about running OH on a NAS is enough people have problems that I don’t recommend it.

You can try to download the 2.5.12 zip file from the link I provided above and see if that works. Or you can figure out how to build the spk using the source at that repo. Beyond that I don’t have any suggestions.

Thank you very much for your support, I really appreciate it.
Unfortunately my Synology NAS does not support Docker.
I have installed a pre-release of 3.0.0.0 now. It needs Java11 which I have to install manually somehow.
I hope I manage to do this installation through SSH.

I am new to the community. Do I need to close this thread somehow?

No. Perhaps someone will happen along with an answer. In 30 days if there is no more activity it will close on its own.