Install headless on Linux 20.04 RUST PANICKING

Hi - looking for ideas on this, as it is the first time I've seen it...

I download and install the client app on a Linux Ubuntu 20.04 server, set up on AWS. All seems to go well until I issue:

 

~/.dropbox-dist/dropboxd

 

I get the following few lines of extensions loading, followed by an aborted start:

 

dropbox: load fq extension '/home/ubuntu/.dropbox-dist/dropbox-lnx.x86_64-126.4.4618/cryptography.hazmat.bindings._openssl.cpython-38-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/ubuntu/.dropbox-dist/dropbox-lnx.x86_64-126.4.4618/cryptography.hazmat.bindings._padding.cpython-38-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/ubuntu/.dropbox-dist/dropbox-lnx.x86_64-126.4.4618/psutil._psutil_linux.cpython-38-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/ubuntu/.dropbox-dist/dropbox-lnx.x86_64-126.4.4618/psutil._psutil_posix.cpython-38-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/ubuntu/.dropbox-dist/dropbox-lnx.x86_64-126.4.4618/apex._apex.cpython-38-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/ubuntu/.dropbox-dist/dropbox-lnx.x86_64-126.4.4618/tornado.speedups.cpython-38-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/ubuntu/.dropbox-dist/dropbox-lnx.x86_64-126.4.4618/wrapt._wrappers.cpython-38-x86_64-linux-gnu.so'
dropbox: load fq extension '/home/ubuntu/.dropbox-dist/dropbox-lnx.x86_64-126.4.4618/PyQt5.QtWidgets.cpython-38-x86_64-linux-gnu.so'
RUST PANICKING -- "Failed to run Python command!" at "app/lib/core/bootstrap/src/python.rs":127
Aborted (core dumped)

 

Is this a file permission issue, or something incompatible with Ubuntu 20.04? What would you suggest I do to investigate it? I've already followed the 'Advanced Re-install' procedure, but ended up at the same point. I've had this working on a non AWS server before, but just can't seem to get it working on AWS.

Thanks in advance for any suggestions!