Please help us help you and fill where relevant:
Your LimeSurvey version:  LimeSurvey Community Edition  (Version 5.6.10+230313)
Own server or LimeSurvey hosting: LimeSurvey
Survey theme/template: extends_fruity
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Hi there,
Hoping someone can please help me understand an issue I am having. I have been working on building a large survey over the past two weeks with no issues and have activated the survey multiple times. On Friday, I made a series of changes, activated it, tested it, filtered responses. This morning, I opened up my laptop and accessed the website, and maybe 3 days of work has just vanished, i.e., settings changes have reverted, questions are gone / unedited, the survey is not activated and all my test responses have vanished too.

Does anyone know what may have caused this - is it possibly the update released today? 

Hi,
either it's the Community Edition - which is hosted on an own server - or it's the Cloud Edition - hosting at LimeSurvey GmbH.
So what do you use?

If you use the at LimeSurvey hosted version you should contact their support.

Joffm