The college applications process is fraught with anxiety for students.

The last thing they need is a major technological glitch.

But in recent months, students across the country have encountered numerous glitches in the Common Application site they use to apply to more than 500 colleges and universities.

The site wouldn't let them submit forms, deleted entire portions of essays, and at times even charged twice for the same application. In some cases, students who thought they submitted applications learned that they hadn't even gone through.

It has caused a wave of concern among students and families who are applying early to colleges this year. The early applications are due for most colleges in mid-October through early November.

"I can't log into my Common App. It says my user name and password is incorrect even though it is not, and when I click 'forget password,' it does not send a reset link," Ramya Rupanagudi wrote on Common App's Facebook (FB) page.

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Matt Walz wrote that his entire essay was deleted and that he had to spend an hour retyping what he lost. Cathy Wood's daughter couldn't upload her letter of recommendation. Margaret Owens Rieger said that colleges she applied to never received her transcripts or essays. Evan Benford was charged twice.

The Common App lets students fill out a single application for multiple colleges, including the vast majority of the country's top-tier schools. The site's popularity has skyrocketed, with the number of applicants nearly doubling in the last five years to more 700,000.

The website's software was overhauled in August. Since then, students and universities have experienced a litany of issues.

The site lists about 15 problems in the "Known Issues" page. All of them are in the process of being fixed, the site says.

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But many students are worried that it will be too late.

Huai Julie wrote on Facebook that she was having trouble submitting her application.

"If this problem cannot be solved, it means I will [lose] my application opportunity," she wrote.

Some colleges have taken steps to address the issue, warning of the processing problems in their own websites. Others, like The University of North Carolina and Georgia Tech, extended their deadlines from from Oct. 15 to Oct. 21.

"We are in regular communication with the Common Application, which is doing their best to resolve these issues," UNC's wesbsite said.

Common Application did not respond to requests for comment.