There is a bug in stm32l1xx_hal_conf.h. The MSI_VALUE value is wrong.
DeviceId = STM32L151RETxFirmwarePackage = STM32Cube FW_L1 V1.10.2Bug in: stm32l1xx_hal_conf.hOn row 110. The MSI_VALUE is defined as 16000000. It should be defined as 2097152 Hz/** * @brief Internal Multiple Speed oscillator (MSI) default value. ...