The National Union of Journalists has accused Johnston Press of making staff on its Sheffield Star title "look stupid" claiming the rushed introduction of the Atex production system lead to a serious front page error.
The Star apologised to readers last week after its attempt to show a "rogues' gallery" of a dozen men involved in a train brawl failed when a "production error" led to all but a quarter of each image being blacked out.
A second Johnston Press paper, the South Yorkshire Times, also suffered with blank areas appearing on its pages.
Chris Morley, NUJ Northern organiser, said the mistake followed warnings to Johnston Press that the controversial new Atex system was "unproven, untried and untested".
Morley said: "We [NUJ] said it was being implemented to a totally unrealistic timescale with woefully inadequate training and support locally.
"The net result is a publishing disaster that is seriously impacting on the health and well being of members, putting some on the edge of physical breakdownsâ€¦
"Journalists are proud that their local papers are a vital part of local communities, so that the damage done to the quality of those papers by Johnston group's ill-considered introduction of the Atex system is a matter of serious professional concern.
"Bluntly, our members don't like being made to look stupid because of stupid management decisions."
The introduction of Atex system, which does away with the need for large numbers of sub-editors by allowing journalists to write into page-ready templates, has already proved to be hugely controversial for Johnston Press.
Union members across the group are expected to ballot later this month on a possible group-wide strike over the introduction of the Atex system and concerns about low staffing levels.
Johnston Press declined to comment.