Trouble flashing code to nrf52

Question

Hi. 
 I have NRF52 DK. 
 I have successfully flashed TWI sensor example on to the board. 
 However, when I move forward with other projects in SDK like ble_app_uart and ble_app_blinky and flash it onto the board, it does without error. 
 But when I check it with terminal like putty, I see "TWI sensor example started" on pressing reset button, which means old application is running on the board and new application is not flashed. 
 What could be the problem? Please help. 
 
 I have done build->rebuild->download 
 Below is the build and flash output for ble_app_uart : 
 
 *** Using Compiler 'V5.06 update 6 (build 750)', folder: 'C:\Keil_v5\ARM\ARMCC\Bin' Rebuild target 'nrf52832_xxaa' compiling boards.c... compiling bsp.c... compiling utf.c... compiling main.c... compiling bsp_btn_ble.c... compiling ble_advdata.c... compiling ble_advertising.c... compiling ble_link_ctx_manager.c... compiling ble_conn_params.c... compiling ble_conn_state.c... compiling ble_srv_common.c... compiling nrf_ble_gatt.c... compiling nrf_ble_qwr.c... compiling ble_nus.c... compiling nrf_drv_uart.c... compiling nrf_drv_clock.c... compiling nrfx_clock.c... compiling nrfx_power_clock.c... compiling nrfx_gpiote.c... compiling nrfx_prs.c... compiling nrfx_uart.c... compiling nrfx_uarte.c... compiling app_button.c... compiling app_error.c... compiling app_error_handler_keil.c... compiling app_error_weak.c... compiling app_fifo.c... compiling app_scheduler.c... compiling app_util_platform.c... compiling app_uart_fifo.c... compiling app_timer.c... compiling hardfault_implementation.c... compiling nrf_assert.c... compiling nrf_atfifo.c... compiling nrf_atflags.c... compiling nrf_atomic.c... compiling nrf_balloc.c... compiling nrf_fprintf_format.c... compiling nrf_fprintf.c... compiling nrf_memobj.c... compiling nrf_ringbuf.c... compiling nrf_pwr_mgmt.c... compiling retarget.c... compiling nrf_section_iter.c... compiling nrf_strerror.c... compiling nrf_log_backend_serial.c... compiling nrf_log_default_backends.c... compiling nrf_log_backend_rtt.c... compiling nrf_log_str_formatter.c... compiling SEGGER_RTT.c... compiling nrf_log_frontend.c... compiling SEGGER_RTT_Syscalls_KEIL.c... compiling SEGGER_RTT_printf.c... compiling nrf_sdh.c... compiling nrf_sdh_ble.c... assembling arm_startup_nrf52.s... compiling system_nrf52.c... compiling nrf_sdh_soc.c... linking... Program Size: Code=23680 RO-data=3552 RW-data=304 ZI-data=12552 FromELF: creating hex file... ".\_build
rf52832_xxaa.axf" - 0 Error(s), 0 Warning(s). Build Time Elapsed: 00:01:17 Load "C:\Users\patel123\Downloads\nRF5_SDK_15.2.0_9412b96\nRF5_SDK_15.2.0_9412b96\examples\ble_peripheral\ble_app_uart\pca10040\s132\arm5_no_packs\_build\nrf52832_xxaa.axf" Set JLink Project File to "C:\Users\patel123\Downloads
RF5_SDK_15.2.0_9412b96
RF5_SDK_15.2.0_9412b96\examples\ble_peripheral\ble_app_uart\pca10040\s132\arm5_no_packs\JLinkSettings.ini" * JLink Info: Device "NRF52832_XXAA" selected. JLink info: ------------ DLL: V6.32i, compiled Jul 24 2018 15:19:55 Firmware: J-Link OB-SAM3U128-V2-NordicSemi compiled Jul 12 2018 11:44:41 Hardware: V1.00 S/N : 682843855 * JLink Info: Found SW-DP with ID 0x2BA01477 * JLink Info: Found SW-DP with ID 0x2BA01477 * JLink Info: Scanning AP map to find all available APs * JLink Info: AP[2]: Stopped AP scan as end of AP map has been reached * JLink Info: AP[0]: AHB-AP (IDR: 0x24770011) * JLink Info: AP[1]: JTAG-AP (IDR: 0x02880000) * JLink Info: Iterating through AP map to find AHB-AP to use * JLink Info: AP[0]: Core found * JLink Info: AP[0]: AHB-AP ROM base: 0xE00FF000 * JLink Info: CPUID register: 0x410FC241. Implementer code: 0x41 (ARM) * JLink Info: Found Cortex-M4 r0p1, Little endian. * JLink Info: FPUnit: 6 code (BP) slots and 2 literal slots * JLink Info: CoreSight components: * JLink Info: ROMTbl[0] @ E00FF000 * JLink Info: ROMTbl[0][0]: E000E000, CID: B105E00D, PID: 000BB00C SCS-M7 * JLink Info: ROMTbl[0][1]: E0001000, CID: B105E00D, PID: 003BB002 DWT * JLink Info: ROMTbl[0][2]: E0002000, CID: B105E00D, PID: 002BB003 FPB * JLink Info: ROMTbl[0][3]: E0000000, CID: B105E00D, PID: 003BB001 ITM * JLink Info: ROMTbl[0][4]: E0040000, CID: B105900D, PID: 000BB9A1 TPIU * JLink Info: ROMTbl[0][5]: E0041000, CID: B105900D, PID: 000BB925 ETM ROMTableAddr = 0xE00FF000 * JLink Info: Reset: Halt core after reset via DEMCR.VC_CORERESET. * JLink Info: Reset: Reset device via AIRCR.SYSRESETREQ. Target info: ------------ Device: nRF52832_xxAA VTarget = 3.300V State of Pins: TCK: 0, TDI: 1, TDO: 1, TMS: 1, TRES: 1, TRST: 1 Hardware-Breakpoints: 6 Software-Breakpoints: 8192 Watchpoints: 4 JTAG speed: 1000 kHz Erase Done. Programming Done. Verify OK. * JLink Info: Reset: Halt core after reset via DEMCR.VC_CORERESET. * JLink Info: Reset: Reset device via AIRCR.SYSRESETREQ. Application running ... Flash Load finished at 10:20:22