Education secretary Michael Russell has conceded that the new version of Glow, Scotland's online network for schools, is facing problems and that schools will need extra support to implement it.
Concern is mounting that the huge task of transferring data from the old Glow may have damaging knock-on effects for schools as they implement the new National qualifications this year.
"Present difficulties in importing information from the old Glow to the new Glow has taken longer than expected," Mr Russell told an audience at the Scottish Learning Festival in Glasgow last week. He said he was aware of teachers' impatience with the slow pace of progress.
And speaking at the Scottish Parliament on Wednesday, Mr Russell said that Education Scotland would be writing to education directors to offer them support in making the transition.
The EIS teaching union has raised concerns with both Education Scotland and the Scottish Qualifications Authority over the use of Glow as the access point for new materials to support Curriculum for Excellence and, in particular, the Nationals.
"There are access issues in a number of areas and this led to authorities having to transfer and replicate resource materials on to their systems, which has caused delay in these being available to teachers," general secretary Larry Flanagan said.
"While the existing Glow system is working effectively in parts of the country, there are some authorities that have essentially stopped using it for various reasons, which means that the delay in the arrival of new Glow is increasing levels of concern and frustration in schools."
The current Glow contract with RM Education is due to end in December, when all information should have been transferred to a new version operating through Microsoft's Office 365 services.
A spokeswoman said that 20 local authorities had already moved all or most of their content to the new service. "The Glow migration was always going to be a significant piece of work, where we are moving all local authorities and their varying levels of content to the new system," she said.
"This process has had its challenges but we are pleased to say it is approximately 50 per cent complete. Significantly, we have already successfully moved the 10 largest - in terms of content - local authorities to the new system, and we are confident that all local authorities will be on the new system by December."
A major critic of the changes to Glow has been Jaye Richards-Hill, a member of the national ICT in Education Excellence Group that reported to the Scottish government in January.
Writing in her personal blog, she says: "Any local education authority or independent school which might be thinking about how to move forward with Glow should stop right now.
"They would be crazy to even consider Glow as a part of any development planning for at least the next school year until the picture becomes clearer and the product workable."
The plan to transfer all the old Glow's content has been controversial, as most of the data it held is not used any more and some argued that the new version should start with a clean slate.
John McCarney, project director for RM Education in Scotland, said: "The migration has been a very challenging process, but it is on schedule. We started at the beginning of July and said it would take up to six months."