Please help us help you and fill where relevant:
Your LimeSurvey version: Cloud 5.3.25
Own server or LimeSurvey hosting: Limesurvey
Survey theme/template: Fruity
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I designed a survey in LimeSurvey Cloud and I want to migrate it to LimeSurvey Community Edition - Version 3.27.12+210816. But I am getting this message:

"error the file is not compatible with this limesurvey version"

Any idea?
Thank you in advance.

Hi,
yes, this is correct.

You can't import an export of version 5.x (4.x as well) into version 3.x.

With version 4.x. the structure of the database was changed for better management of multilingual surveys.

Up to version 3.x. there was is record in the database table for each language, what is an unnecessary waste of space.
Now there's only one general record and the language sensitive parts are in additional "language" tables.

If you install the Community Edition 5.x. you see this by comparing the structure of the databases.

Joffm 

There is currently no difference between the Cloud and Community version in terms of survey import and export.
It is possible to migrate a survey from LS Cloud to Community, as long as the LimeSurvey version of the target system is not lower than the source system.

Examples:
From LS3 to LS5 is working.
From LS3 to LS3 is working.
From LS5 to LS3 is NOT working.
 

Thank you guys.

 
Since I recently faced the same challenge of importing a survey created with Limesurvey v 5.x into an older 3.x version, I am sharing my solution:

1. Export the survey at LS 5.x as tab separated value format
2. Open the TXT file with a text editor
3. Remove these two rows:
   1. ipanonymize
   2. tokenencryptionoptions
4. Save as TXT file
5. Import at LS 3.x

Depending on your survey structure and complexity, there could be further challenges to solve.