I get a similar error and also not behind a proxy.
error message:
Request sent successfully.
Request sent successfully.
Email or password is invalid!
I added -consoleLog to the command got the following ( there were quite a lot of similar messages ie “…Could not install bundle…” - i have trimmed to the last 4 )
...!ENTRY org.eclipse.update.configurator 4 0 2018-05-01 17:11:20.056
!MESSAGE Could not install bundle plugins/org.apache.poi.ooxml.schemas_3.9.0.v201405241750.jar A bundle is already installed with the name "org.apache.poi.ooxml.schemas" and version "3.9.0.v201405241750"
!ENTRY org.eclipse.update.configurator 4 0 2018-05-01 17:11:20.077
!MESSAGE Could not install bundle plugins/org.eclipse.ui.browser_3.5.2.v20161114-0210.jar A bundle is already installed with the name "org.eclipse.ui.browser" and version "3.5.2.v20161114-0210"
!ENTRY org.eclipse.update.configurator 4 0 2018-05-01 17:11:20.092
!MESSAGE Could not install bundle plugins/org.eclipse.equinox.concurrent_1.1.0.v20130327-1442.jar A bundle is already installed with the name "org.eclipse.equinox.concurrent" and version "1.1.0.v20130327-1442"
!ENTRY org.eclipse.update.configurator 4 0 2018-05-01 17:11:20.110
!MESSAGE Could not install bundle plugins/org.apache.commons.io_2.4.0.jar A bundle is already installed with the name "org.apache.commons.io" and version "2.4.0"
My email and password are correct ( the same as i use to login to the forum ) - is the above causing the error?