Incompatibilty between the computers in Scotland's schools and the new computer system at the Scottish Qualifications Authority (SQA) has led to delays in sending out exam results and possible inaccuracies in some of the certificates received.
As a result, universities cannot confirm places for the new term, which starts in October, before the SQA has completed double-checking every paper this week.
Each school had to prepare a file on every student sitting an exam and this information was then put onto disc and sent for registration to the SQA.
However, the new computer, could not read the disc and the schools were asked to resubmit all the data on paper so that SQA staff could type the information into the computer.
This led to thousands of mistakes and gaps. SQA was forced to guess how many students were taking which exam, with the inevitable result that there was a chronic shortage of some exam papers.
The computer at the SQA was then found to be missing some records of internal assessments which students had sat during the year and which contributed to their final marks.
Computer problems originated with the decision to revamp the whole qualifications and exam system in Scotland. The systems of the Scottish Examination Board and the Scottish Vocational Education Council, which merged to form the SQA three years ago, were incapable of supporting the processing of all SQA qualifications and the single certificate.
It was decided to develop a new IT system, which is now the largest Ingres-based software development in the UK. During the development of the system software, supplier Phoenix was involved.
The new computer system was installed earlier this year and it was known by mid-July that the SQA system and the schools' computers were incompatible, but too little was done to avert the crisis.
Dennis Gunning, the SQA's director of development, has called for feedback from the schools as soon as they return. "We want diagnostic tests on our database so we are confident information is accurate," he said.
In an agreed statement issued on 13 August with the SQA's David Caldwell, the director of the Committee of Scottish Higher Education Principals, said, "All indications are that the results for the vast majority of candidates are both accurate and complete."