As it stands, the college in the town centre has no access to the internet.
A statement on the OSFC website said there are online lessons for the Upper Sixth, but no lessons for the Lower Sixth.
It comes a week after the start of term at the college on Union Street.
The OSFC statement reads: "Unfortunately, college will be closed on Monday 11 September 2023, due to a serious IT failure.
"All internet, wifi and online facilities are unavailable on site, including access to Cedar and timetables/room info.
"We are delivering online lessons to Year 13 students ONLY, as they are experienced using our systems and all have Chromebooks.
"Year 12 will not be in college and will not have lessons.
"We will be in contact soon via email with further details for all students.
"Thank you for your patience and understanding."
