For the second time in two years, New York officials reported problems with computer-based tests Tuesday, causing headaches for students and educators across the state.

Questar Assessment, Inc., which develops New York state’s third-through-eighth grade reading and math exams, “experienced delays at some schools this morning,” affecting computer-based reading tests, said Emily DeSantis, a spokeswoman for the state education department.

It was not immediately clear exactly how the problems were playing out in schools. Some students had trouble downloading the test and submitting their responses, according to an alert on the state’s website. State officials characterized the problems as “intermittent” and emphasized that thousands of students were able to submit their exams.

Other groups reported more serious problems. In some cases, students lost their work and had to start over, according to the state’s Council of School Superintendents. State officials did not immediately respond to a request for comment on that claim.

The problems are likely to have limited impact in New York City, which has been slower to adopt computer-based testing. Just 25 city schools are using electronic tests this cycle, according to the city’s education department. The rest of the city’s schools use paper tests.

State officials could not immediately say how many students experienced issues or what caused them, but noted 25 percent of all schools across the state employ electronic tests. As a result of the snafus, schools using electronic tests will not administer them on Wednesday. It was not clear when they would resume.

The computer meltdowns are the latest strike against Questar and could complicate the state’s efforts to expand the use of computer-based testing to every school. Questar currently has a $44 million contract with the state through 2020 and has struggled with testing problems in other states.

Tennessee officials were closely watching the company’s response in New York, as they also have struggled with online testing problems in recent years and are gearing up to administer state tests through Questar later this month.

“We are working with the vendor to determine if the events that occurred in New York could happen in Tennessee and will assess appropriate action as soon as the root cause of the New York incident is known,” said AE Graham, a spokeswoman for Tennessee’s education department.

In a statement, Questar officials emphasized that they are “proactively” working with New York’s education department.

Some activists who support boycotting state tests seized on the problems to raise broader objections to testing, while others said the latest issues raise questions about Questar’s ability, in particular, to administer electronic tests smoothly.

“The problems schools have encountered this year and last lead us to doubt that the state’s current testing vendor, Questar Assessment, can ever produce acceptable results,” said Bob Lowry, deputy director of the New York State Council of School Superintendents, which has supported the transition to electronic tests.

Others were more optimistic. “It is clear that they are taking these technical issues seriously and responding to them appropriately,” said Ian Rosenblum, executive director of The Education Trust-New York, an advocacy group that generally supports the assessments. Referring to anti-testing activists, he added: “We wish that the opponents of state assessments would stop politicizing the tests while students are taking them.”