Problems with last year's trials meant on-screen training was scrapped.
Primary schools have had difficulty accessing the online register system.
Markers have received multiple contracts, sometimes for the wrong subjects. Some have also been contacted and asked to sign contracts they have already signed.
Many markers received details of training venues very late, and some were not told where to go. Others had to travel hundreds of miles. In previous years, markers saw papers up to a month in advance. This year they did not see them before training because of fears over leaks. This meant markers struggled with scripts they had not had time to get to know.
There have been repeated problems with the online systems that check the accuracy of teachers' marking. Teachers complained that the text was hard to read and that the computers often crashed. Quality assurance checks for key stage 3 English markers initially failed everyone due to a computer error.
In the past, examiners began marking and were then asked to send a sample of their work to a supervisor. Now, they complete an on-screen exercise before marking and at intervals during their work. This means there are now no checks on "live" scripts, though the regulator says the new checks are more consistent.
There have been widespread complaints of scripts being delivered late or not at all, and some markers have received the wrong papers. ETS was forced to offer pound;250 to examiners who received no papers.
Markers have complained of difficulties getting ETS to respond when a child is listed by the computer as having taken a test, when they have no papers for him or her, and vice versa.
Markers have spent hours on hold to a helpline only to find staff at the other end of little help. Emails have also gone unanswered. This year, for the first time, the helpdesk has been outsourced. Some markers said its staff had little knowledge of testing, and even that some had a poor command of English.
Extra checks on the papers of pupils who were found to be just below a national curriculum level have been scrapped this year. ETS says the new marker checks make it redundant, while the regulator has argued it is wrong to check papers found to be just below a national curriculum level and not to check those just above it.