All shows, including the annual Christmas pantomime, have been cancelled after crumbling concrete was found in a theatre.
Redbridge Council has been forced to close the Kenneth More Theatre, in Oakfield Road, Ilford, to keep people safe while repairs to the building take place.
RAAC (reinforced autoclaved aerated concrete), a lightweight concrete used in construction of the theatre in 1975, has degraded and must be replaced.
Engineers have conducted a detailed structural survey to assess the building and "significant work" needs to be carried out to remove the RAAC concrete over the next few months.
"We have had to relocate or cancel the immediate shows and events planned in this venue," a spokesperson for Redbridge Council said.
"We share your disappointment that shows throughout the autumn and winter and into next year will not be able to go ahead in the Kenneth More Theatre.
"This includes our beloved annual pantomime, Jack and the Beanstalk, which we have had no choice but to cancel.
"We understand how disappointing this is, as many people look forward to this as a traditional celebration with family and friends. We have not taken this decision lightly."
They said ticket holders will be updated, and refunds for cancelled shows will be processed automatically.
People are not to contact the Box Office as they are working to process these transactions.
The council said it was doing all it can to keep the tradition alive for visitors and are committed to staging a Christmas show at the Redbridge Drama Centre.
"Although the venue accommodates far smaller-scale productions than the one originally scheduled for the theatre, it will still be full of fun, song, and Christmas spirit."
Council officers are contacting the theatrical groups and organisations that have booked the Kenneth More Theatre and will offer alternative spaces where possible, but there is no like-for-like venue in the borough.
"We know this thriving theatre is as important to many local people as it is to us, and we apologise to the theatrical groups and audience members for the disappointment this will cause them," the spokesperson added.
"We will work relentlessly to ensure that our theatre comes back shining brighter.
"We assure you that the work undertaken will ensure that we have a theatre in Redbridge for many years to come.
"Thank you for understanding that we must and always will put the safety of staff, performers, and audience members first."
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