Technical glitches and exam woes which hampered the Chartered Insurance Institute this year have affected 850 candidates, according to the professional body.
In an apology sent to candidates yesterday (October 27) the CII said it was "extremely sorry" the issues had caused "significant stress and disruption" to hundreds of students.
But the professional body said not all of these 850 candidates failed, despite the technical challenges they encountered.
The CII was plagued by a string of glitches as it moved its exams online this summer amid the crisis.
In July and August FTAdviser reported how advisers were repeatedly falling foul of the issues, with some dubbing the process an "absolute disgrace".
But the technical issues continued in test centres across the country this month, with numerous candidates claiming their computer system froze or shut down hours into the exam.
In yesterday's apology Gill White, chief customer officer of the CII, said the operational challenges of providing a full exam service whilst adhering to all local coronavirus guidelines had been "significant".
Ms White said: "Our job is to make the sitting of exams as seamless and stress free as possible during an inevitably tense time and letting down even one student in that regard is not acceptable to us.
"We understand the significant distress the exam issues have caused and deeply regret that this has happened."
Ms White said the CII had partnered with a new remote invigilation supplier in January, which would allow exams to be sat "24/7/365 days a year, across the world, via centres and online".
She added: "While the majority of CII’s 18,500 July and October exam sittings since March have completed without incident, we are acutely aware of unacceptable instances where there were problems in accessing remote invigilation sessions, accessing preferred exam centres and a series of technical issues during sittings."
Ms White said the CII was working closely with its invigilation provider to resolve all the issues encountered by candidates this year and ensure future students had "the best experience possible".
A catalogue of errors
During the remote exam fallout this summer some advisers claimed they had been left in the dark by the professional body throughout the process, with candidates unable to contact the CII via email or telephone for updates.
In response to the backlash, the professional body confirmed it would be offering a free October re-sit to all candidates who failed the remote exams in July, regardless of whether they reported technical issues at the time.
Last month, the CII wrote to more than 4,500 candidates set to sit exams in October, warning their timetable may change to comply with coronavirus safety measures at test centres.
The changes, intended to ensure the safety of candidates, meant some did not get a place at their preferred test centre. The professional body promised an alternative sitting would be arranged free of charge before April next year.