
Samsung Galaxy Folder
The latest firmware for Samsung Galaxy Folder (SM-G150NL) is G150NLKLU1APK3 with Android 5.1.1 (Lollipop), released on November 27, 2016 for 1 region (CSC). Every official firmware build for SM-G150NL, newest first: one row per build with all regions (CSC) that received it.
Each firmware build has its own page at https://samfirm.shop/build/{PDA}, where {PDA} is the build number from the list above. Example: https://samfirm.shop/build/G150NLKLU1APK3
All 4 builds in our database run Android 5.1.1 (Lollipop). The newest build, G150NLKLU1APK3, was released on November 27, 2016. No new build has appeared for 120 months, so regular updates for this model have most likely ended.

SM-G150NS

SM-G165N

SM-G160N

SM-G3509

SM-G3589W
The newest firmware for SM-G150NL runs Android 5.1.1 (Lollipop): build G150NLKLU1APK3, released on November 27, 2016.
The latest build for SM-G150NL, G150NLKLU1APK3, was released on November 27, 2016 (9 years ago).
SM-G150NL has had no new firmware for 120 months, so regular updates have most likely ended.
Yes, all firmware files for SM-G150NL are 100% official, original, and obtained directly from Samsung servers.
To flash SM-G150NL, you need to download the appropriate firmware, put your device into Download Mode, and use the Odin tool to load the BL, AP, CP, and CSC files.
Downgrading is only possible if the bootloader version (binary bit) of the old firmware matches the current one. Always check the binary version before flashing SM-G150NL.