How to fix Visual Studio throwing a “This syntax requires an imported helper named ‘__spreadArray’ which does not exist in ‘tslib’. Consider upgrading your version of ‘tslib’.

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Fixing “This syntax requires an imported helper named ‘__spreadArray’ which does not exist in ‘tslib’. Consider upgrading your version of ‘tslib’ in Visual Studio

1. Ignore the error

   Just ignoring the error might work. There’s a non-zero chance that the error won’t actually stop you from building and debugging.
   
   If actually DOES fail your build, proceed.

2. Clean your solution and rebuild

   If cleaning and rebuilding your solution still doesn’t help, well, there are more steps below.

3. Restart Visual Studio

   This sounds stupid, but it might help – and even if it doesn’t, restarting Visual Studio is reasonably quick to do. Nowadays, anyway.

4. Update your tslib

   Updating your tslib version might be helpful if you’re using an older version than 1.10.0. You should probably be running something more recent than that, as it was published sometime in 2019 :)

5. Just reinstall the package

   Ok, so if everything else fails, this has worked for me every single time.
   
   Just run the command below:
   npm install tslib@latest --save
   
   Or if you actually know which version you want to use, run it like this:
   npm install tslib@[your-preferred-version]latest --save