Fingerprint unlock

Greetings everyone

I have a problem with fingerprint unlock in Codebook. I have a Xiaomi Redmi Note 4 (Android) using Lineage OS 15.1 and had a support issue open at the time that has been closed, but I’m still wondering about this…


  • Lineage OS is a custom ROM
  • They state on their page that there exists an issue with the hardware maker of the finger print sensor

This was the reason my support issue was closed…

However, I really, really question the fingerprint unlock implementation that Codebook uses because every single other app that I have, including the very OS itself that unlocks the phone, is able to use fingerprint unlock / authentication. Codebook is ONLY ONE not being able to use fingerprint unlock. I just don’t understand this. The phone is not rooted, although I know that’s not an issue. Codebook fingerprint unlock worked with Xiaomi’s MIUI. I’m using Lineage OS because Xiaomi won’t release an Android O or later version for the RedMi Note 4.

My only conclusion is that the way Codebook calls the fingerprint api, is causing failure with this setup as every other app (Paypal etc.) can use fingerprint unlock.

Any positive ideas?

Hello @Johannes_De_Beer

Thank you for your follow-up regarding the fingerprint scanner issue you are experiencing. We can certainly understand the desire to utilize the fingerprint scanner to streamline accessing your data within Codebook for Android. I’m certain that is frustrating.

Unfortunately, there is a large array of Android devices on the market and we are unable to test against all devices, supporting non-OEM operating system’s increases the testing coverage area considerably.

As you mentioned above: Lineage OS is a custom ROM, and there are reports of finger print sensor issues. From our previous conversation, you mentioned that you used Xiaomi prior to Lineage OS on the same device and were able to use the fingerprint scanner successfully with Codebook for Android. Would it be possible to revert back to Xiaomi and see if the issue is resolved in Lineage at a later release?

Hi Nick, I would prefer not to go back. I may some day to see what Xiaomi is up to, but around the time I switched to Lineage they removed their ROM downloads page in a rebuilding process and it became a mess to update on Xiaomi.