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`type 'Null' is not a subtype of type 'bool'` when creating file

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  • Flutter
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hamed
12 Feb, 2026, 22:31

When creating a new file using Appwrite Flutter SDK, the file is successfully created on the server, but the client throws the following exception:

TypeScript
type 'Null' is not a subtype of type 'bool'
  • Self hosted: 1.8.1
  • Flutter SDK: 21.0.0

Althouh i know that this error occured when theris a missmated betwen sdk but for this error i have bothe latest appwrite version 1.8.1 and it flutter lasted sdk 21.0.0 and still facing this

TL;DR
Issue: Error `type 'Null' is not a subtype of type 'bool'` occurs when creating a file using Appwrite Flutter SDK. Solution: This error can occur due to a mismatch between the SDK versions. Despite having the latest versions of Appwrite (1.8.1) and Flutter SDK (21.0.0), the error persists. Make sure to check for any possible compatibility issues between the versions being used by the developers.
hamed
12 Feb, 2026, 22:38

type 'Null' is not a subtype of type 'bool' when creating file

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