The state’s year-end testing has been interrupted by a major computer glitch — stopping more than 18,000 public school students from completing their assessments.

The Utah Board of Education announced the technical issue Friday. And it comes as the state implements a new standardized test this year, known as RISE, run by a different vendor than schools have previously used.

“We were planning for — though not expecting — the kinds of issues associated with any new computer testing system,” Darin Nielsen, the state’s assistant superintendent of student learning, said in an emailed statement, “and [we] have been transparent with districts and charter schools about problems affecting our students during the winter and spring testing windows.”

Students in third through eighth grades are impacted by the problem. The service interruption was first reported Thursday, and the state board is working with the test vendor — Questar Assessment Inc. — to gauge the full scope.

The exams focus on language arts, writing, science and math and are used by the state to assess how well students are improving year to year. Results can tell teachers, most importantly, who is falling below grade level.

Annual testing is required by federal law in grades three through eight (as well as at least once in high school). Utah, though, has expanded different versions of the exam to include all grade levels so it can generate data on performance. Those scores are then used to determine what schools get funding, how they’re graded statewide and which ones are struggling enough to possibly merit closure.

The state switched vendors last year after previously contracting with American Institutes for Research to conduct what was then called the SAGE test. It entered into a new agreement with Questar, headquartered in Minnesota, for $30 million in late 2017. This is the first year under the new model.

SAGE had failed to gain traction in Utah since it was implemented in 2013. More and more parents each year opted their students out of the test. That is allowed under state law, though the school board has said it undermines the accuracy of using the exams for accountability rankings.

Most board members had hoped the new RISE tests would encourage more parents to have their kids take the assessment.

The computer issues this week impact those who took the exam Thursday or tried to take the science exam Friday. The state reported that those who have not yet taken a RISE assessment or completed one before that window are not impacted.

The glitch occurred around 10:45 a.m. Thursday when the vendor’s servers dropped in and out of service, according to the state’s announcement. Those taking the tests received error notices when they tried to submit their answers.

So far this year, more than 85,000 students have taken these tests. Roughly 18,000 were not able to successfully complete theirs. That’s 6 percent of the state’s public third through eighth graders.

Another 2,300 have not yet started with the testing window still open for several weeks.

The state said in its news release that it anticipates the vendor will be able to recover the responses for those who were interrupted. It expects the issue to be resolved by Monday.