Corruption in the phone’s permanent storage sections where IMEI is stored can cause write failures. The target may return a "write protected" or "invalid address" error. This is common after failed OTA updates or flashing of incompatible firmware.
How to fix an invalid IMEI issue on your smartphone - Airtel
If the NVRAM or NVDATA partitions are wiped or corrupted during a firmware flash, the device may reject new IMEI data. write imei to target failed
This error typically occurs when using engineering tools (like Maui META, SPD Upgrade Tool, or QPST) to restore or repair a device's IMEI number. It indicates the software cannot write the new IMEI to the phone’s NVRAM (Non-Volatile Random Access Memory) or modem partition.
: QPST (RF_NV Manager), UltraBox, Chimera Tool. Corruption in the phone’s permanent storage sections where
It’s a powerful set of tools, but the learning curve is steep and the Hovatek forums are your best friend for specific error codes."
When you see follow this systematic checklist: How to fix an invalid IMEI issue on
"Write IMEI to target failed"