Redmine

Environment:
Redmine version 3.2.4.stable
Ruby version 1.9.3-p484 (2013-11-22) [x86_64-linux]
Rails version 4.2.7.1
Environment production
Database adapter PostgreSQL
SCM:
Mercurial 4.1
Git 1.9.1
Filesystem
Redmine plugins:
no plugin installed
OS Ubuntu server 14.04.5 LTS
Mercurial 4.1 from either Ubuntu repo's or PyPi.

Moving to Mercurial 4.1 and opening a repo results in:

"The entry or revision was not found in the repository."

and a log entry of:

"Started GET "/projects/hplc/repository" for 174.21.203.58 at 2017-02-03 08:59:47 -0800
Processing by RepositoriesController#show as HTML
Parameters: {"id"=>"hplc"}
Current user: aklaver (id=3)
hg: error during getting info: hg exited with non-zero status: 1
Rendered common/error.html.erb within layouts/base (0.3ms)
Completed 404 Not Found in 574ms (Views: 60.9ms | ActiveRecord: 206.4ms)
"

Restarting the Redmine server does not help.
The only thing that works is rolling back to Mercurial 4.0.2.