Thanks, very kind of you all. Allow me to reply in a single post.
I'm using Lubuntu 18.10 in a VirtualBox VM, practically only for the sake of running Electrum (which can no longer run native in my aged OS). Which is why, generally speaking, I understand very little about Linux. It's very light, and got me rid of many hassles I used to get using Ubuntu 14.04.
Here two screenshots showing this Desktop Configuration File which up to 4.0.2 I clicked on to start Electrum, the first of which I assume was installed by some v. 3.xx (don't ask where that time stamp showing 1970 came from Time and Date are otherwise synchronized as they ought to) the second one is a copy I made for convenience:
[Sorry, goodfolks, I had written this before realising that I can't figure out how to upload a jpeg here any help is welcome] Yes, everything seems fine just clicking on the "run_electrum" file to start 4.0.3. I say "seems", because I've looked around in the GUI, but I haven't attempted any operation yet. And yes, I could launch v.4.0.2 just typing electrum in the Terminal. Not that I was using this method, just clicking on the Desktop Configuration File would launch it immediately. Incidentally, last night I must have tried "run_electrum" in Terminal, but it was late and I can't remember exactly how this here is recovered from the clipboard (including the three """ at the end):
python3 Electrum-4.0.3/run_electrum
/home/lub/Electrum-4.0.3/packages/bitstring.py:36: DeprecationWarning: invalid escape sequence \
"""
I have always used the Terminal to install Electrum, by just following the instructions on the site. Yesterday hadn't mentioned it to avoid clutter I had also downloaded the Appimage. But when I clicked on it, nothing happened, nothing at all.
yarl Any one of those commands gives this:
Command 'pip' not found, but can be installed with:
sudo apt install python-pip
Attempting this, I get what's coming below (sorry, I don't know how to make it shorter). None of it I am able to understand, except of course the 404's which I wouldn't know how to get around.
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
javascript-common libjs-jquery libjs-sphinxdoc libjs-underscore libpython-all-dev libpython-dev
libpython2-dev libpython2.7-dev python-all python-all-dev python-asn1crypto python-cffi-backend
python-configparser python-crypto python-cryptography python-dbus python-dev python-entrypoints
python-enum34 python-idna python-ipaddress python-keyring python-keyrings.alt
python-secretstorage python-setuptools python-six python-wheel python2-dev python2.7-dev
Suggested packages:
apache2 | lighttpd | httpd python-crypto-doc python-cryptography-doc python-cryptography-vectors
python-dbus-dbg python-dbus-doc python-enum34-doc gir1.2-gnomekeyring-1.0 python-fs python-gdata
python-keyczar python-secretstorage-doc python-setuptools-doc
The following NEW packages will be installed:
javascript-common libjs-jquery libjs-sphinxdoc libjs-underscore libpython-all-dev libpython-dev
libpython2-dev libpython2.7-dev python-all python-all-dev python-asn1crypto python-cffi-backend
python-configparser python-crypto python-cryptography python-dbus python-dev python-entrypoints
python-enum34 python-idna python-ipaddress python-keyring python-keyrings.alt python-pip
python-secretstorage python-setuptools python-six python-wheel python2-dev python2.7-dev
0 upgraded, 30 newly installed, 0 to remove and 1 not upgraded.
Need to get 33,6 MB of archives.
After this operation, 63,9 MB of additional disk space will be used.
Do you want to continue? [Y/n] y
Get:1 http://archive.ubuntu.com/ubuntu cosmic/main amd64 javascript-common all 11 [6.066 B]
Get:2 http://archive.ubuntu.com/ubuntu cosmic/main amd64 libjs-jquery all 3.2.1-1 [152 kB]
Get:3 http://archive.ubuntu.com/ubuntu cosmic/main amd64 libjs-underscore all 1.8.3~dfsg-1 [59,9 kB]
Err:4 http://archive.ubuntu.com/ubuntu cosmic/main amd64 libjs-sphinxdoc all 1.7.9-1
404 Not Found [IP: 91.189.88.152 80]
Err:5 http://archive.ubuntu.com/ubuntu cosmic-updates/main amd64 libpython2.7-dev amd64 2.7.16-2~18.10
404 Not Found [IP: 91.189.88.152 80]
Err:6 http://archive.ubuntu.com/ubuntu cosmic/main amd64 libpython2-dev amd64 2.7.15-3
404 Not Found [IP: 91.189.88.152 80]
Err:7 http://archive.ubuntu.com/ubuntu cosmic/main amd64 libpython-dev amd64 2.7.15-3
404 Not Found [IP: 91.189.88.152 80]
Err:8 http://archive.ubuntu.com/ubuntu cosmic/main amd64 libpython-all-dev amd64 2.7.15-3
404 Not Found [IP: 91.189.88.152 80]
Err:9 http://archive.ubuntu.com/ubuntu cosmic/main amd64 python-all amd64 2.7.15-3
404 Not Found [IP: 91.189.88.152 80]
Err:10 http://archive.ubuntu.com/ubuntu cosmic-updates/main amd64 python2.7-dev amd64 2.7.16-2~18.10
404 Not Found [IP: 91.189.88.152 80]
Err:11 http://archive.ubuntu.com/ubuntu cosmic/main amd64 python2-dev amd64 2.7.15-3
404 Not Found [IP: 91.189.88.152 80]
Err:12 http://archive.ubuntu.com/ubuntu cosmic/main amd64 python-dev amd64 2.7.15-3
404 Not Found [IP: 91.189.88.152 80]
Err:13 http://archive.ubuntu.com/ubuntu cosmic/main amd64 python-all-dev amd64 2.7.15-3
404 Not Found [IP: 91.189.88.152 80]
Get:14 http://archive.ubuntu.com/ubuntu cosmic/main amd64 python-asn1crypto all 0.24.0-1 [72,7 kB]
Err:15 http://archive.ubuntu.com/ubuntu cosmic/main amd64 python-cffi-backend amd64 1.11.5-3ubuntu1
404 Not Found [IP: 91.189.88.152 80]
Err:16 http://archive.ubuntu.com/ubuntu cosmic/main amd64 python-configparser all 3.5.0b2-1
404 Not Found [IP: 91.189.88.152 80]
Err:17 http://archive.ubuntu.com/ubuntu cosmic/main amd64 python-crypto amd64 2.6.1-9build1
404 Not Found [IP: 91.189.88.152 80]
Get:18 http://archive.ubuntu.com/ubuntu cosmic/main amd64 python-enum34 all 1.1.6-2 [34,8 kB]
Get:19 http://archive.ubuntu.com/ubuntu cosmic/main amd64 python-idna all 2.6-1 [32,4 kB]
Get:20 http://archive.ubuntu.com/ubuntu cosmic/main amd64 python-ipaddress all 1.0.17-1 [18,2 kB]
Get:21 http://archive.ubuntu.com/ubuntu cosmic/main amd64 python-six all 1.11.0-2 [11,3 kB]
Err:22 http://archive.ubuntu.com/ubuntu cosmic/main amd64 python-cryptography amd64 2.3-1ubuntu1
404 Not Found [IP: 91.189.88.152 80]
Err:23 http://archive.ubuntu.com/ubuntu cosmic/main amd64 python-dbus amd64 1.2.8-2build1
404 Not Found [IP: 91.189.88.152 80]
Err:24 http://archive.ubuntu.com/ubuntu cosmic/main amd64 python-entrypoints all 0.2.3-3
404 Not Found [IP: 91.189.88.152 80]
Get:25 http://archive.ubuntu.com/ubuntu cosmic/main amd64 python-secretstorage all 2.3.1-2 [11,8 kB]
Err:26 http://archive.ubuntu.com/ubuntu cosmic/main amd64 python-keyring all 15.1.0-1
404 Not Found [IP: 91.189.88.152 80]
Err:27 http://archive.ubuntu.com/ubuntu cosmic/universe amd64 python-keyrings.alt all 3.1-1
404 Not Found [IP: 91.189.88.152 80]
Err:28 http://archive.ubuntu.com/ubuntu cosmic/universe amd64 python-pip all 9.0.1-2.3
404 Not Found [IP: 91.189.88.152 80]
Err:29 http://archive.ubuntu.com/ubuntu cosmic/main amd64 python-setuptools all 40.2.0-1
404 Not Found [IP: 91.189.88.152 80]
Get:30 http://archive.ubuntu.com/ubuntu cosmic/universe amd64 python-wheel all 0.30.0-0.2 [36,4 kB]
Fetched 435 kB in 1s (399 kB/s)
E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/s/sphinx/libjs-sphinxdoc_1.7.9-1_all.deb 404 Not Found [IP: 91.189.88.152 80]
E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/p/python2.7/libpython2.7-dev_2.7.16-2~18.10_amd64.deb 404 Not Found [IP: 91.189.88.152 80]
E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/p/python-defaults/libpython2-dev_2.7.15-3_amd64.deb 404 Not Found [IP: 91.189.88.152 80]
E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/p/python-defaults/libpython-dev_2.7.15-3_amd64.deb 404 Not Found [IP: 91.189.88.152 80]
E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/p/python-defaults/libpython-all-dev_2.7.15-3_amd64.deb 404 Not Found [IP: 91.189.88.152 80]
E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/p/python-defaults/python-all_2.7.15-3_amd64.deb 404 Not Found [IP: 91.189.88.152 80]
E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/p/python2.7/python2.7-dev_2.7.16-2~18.10_amd64.deb 404 Not Found [IP: 91.189.88.152 80]
E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/p/python-defaults/python2-dev_2.7.15-3_amd64.deb 404 Not Found [IP: 91.189.88.152 80]
E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/p/python-defaults/python-dev_2.7.15-3_amd64.deb 404 Not Found [IP: 91.189.88.152 80]
E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/p/python-defaults/python-all-dev_2.7.15-3_amd64.deb 404 Not Found [IP: 91.189.88.152 80]
E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/p/python-cffi/python-cffi-backend_1.11.5-3ubuntu1_amd64.deb 404 Not Found [IP: 91.189.88.152 80]
E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/c/configparser/python-configparser_3.5.0b2-1_all.deb 404 Not Found [IP: 91.189.88.152 80]
E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/p/python-crypto/python-crypto_2.6.1-9build1_amd64.deb 404 Not Found [IP: 91.189.88.152 80]
E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/p/python-cryptography/python-cryptography_2.3-1ubuntu1_amd64.deb 404 Not Found [IP: 91.189.88.152 80]
E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/d/dbus-python/python-dbus_1.2.8-2build1_amd64.deb 404 Not Found [IP: 91.189.88.152 80]
E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/e/entrypoints/python-entrypoints_0.2.3-3_all.deb 404 Not Found [IP: 91.189.88.152 80]
E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/p/python-keyring/python-keyring_15.1.0-1_all.deb 404 Not Found [IP: 91.189.88.152 80]
E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/universe/k/keyrings.alt/python-keyrings.alt_3.1-1_all.deb 404 Not Found [IP: 91.189.88.152 80]
E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/universe/p/python-pip/python-pip_9.0.1-2.3_all.deb 404 Not Found [IP: 91.189.88.152 80]
E: Failed to fetch http://archive.ubuntu.com/ubuntu/pool/main/p/python-setuptools/python-setuptools_40.2.0-1_all.deb 404 Not Found [IP: 91.189.88.152 80]
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?