Hi there! I'm really sorry to hear that you're experiencing issues with the Stradivarius app crashing when you try to select the filter option. That must be quite frustrating, but I'm here to help you get through this.

Let’s try a few troubleshooting steps to see if we can resolve this issue:

1. Update the App: First, make sure you’ve got the latest version of the Stradivarius app. Sometimes crashes can happen due to a previous version having bugs. You can do this by going to the App Store, searching for “Stradivarius,” and seeing if there’s an update available.

2. Clear App Cache: Although iOS doesn't have a direct method to clear the cache of specific apps, you can try deleting the app and reinstalling it. This can sometimes help with performance issues. Just tap and hold the app icon, select "Remove App," then reinstall it from the App Store.

3. Restart Your iPhone: Restart your device. This can clear minor software bugs or glitches. Simply press and hold the power button until you see the "slide to power off" option, turn it off, and then turn it back on.

4. Check for iOS Updates: Make sure your iPhone is running the latest version of iOS. Go to Settings > General > Software Update and see if there’s an update available. If so, please update it.

5. Check for Known Issues: There have been some discussions online regarding filtering issues in apps that could relate to your experience. A recent update fixed bugs, so if you've done the above steps and it's still crashing, it might be worth waiting for the next update or checking if there’s an ongoing issue with the filter function.

If none of these steps work, or if you continue to have crashes, you can reach out to Stradivarius support directly at [email protected] for further assistance.

Are you satisfied with the steps I've provided? Let me know if you need more help!