title: can't build with the latest keil MDK version(V5.37)
body: <p>all:
  I updated my keil MDK version to the latest which is V5.37,and then I found that the project can't build anymore.
  since the V5.37 do not support the compiler 5 and set the default compiler to compiler 6,I installed the compiler 5(Arm compiler version 5 ,V5.06 update7) with a independent patch.and then add the compiler 5 to the keil,set the compiler 5 as the default compiler,but keil can't build the project,build output as follows:</p>
  <pre><code>*** Using Compiler 'V5.06 update 7 (build 960)', folder: 'C:\_AnZhuang\keil\Keil\ARMCCv506u7\Bin'
  Build target 'LED'
  assembling startup_stm32f40_41xxx.s...
  startup_stm32f40_41xxx.s: Error: A9511E: Unable to determine the current toolkit. Check that ARM_TOOL_VARIANT is set correctly.
  startup_stm32f40_41xxx.s: Check that your license details are correct in the License Management dialog of MDK. Additional information is available at:
  startup_stm32f40_41xxx.s:  - ARMLMD_LICENSE_FILE: unset
  startup_stm32f40_41xxx.s:  - LM_LICENSE_FILE: unset
  startup_stm32f40_41xxx.s:  - ARM_TOOL_VARIANT: unset
  startup_stm32f40_41xxx.s:  - ARM_PRODUCT_PATH: unset
  startup_stm32f40_41xxx.s:  - Product location: product not found
  startup_stm32f40_41xxx.s:  - Toolchain location: C:\_AnZhuang\keil\Keil\ARMCCv506u7\Bin
  startup_stm32f40_41xxx.s:  - Selected tool variant: mdk_lite
  startup_stm32f40_41xxx.s: Product: unknown
  startup_stm32f40_41xxx.s: Component: ARM Compiler 5.06 update 7 (build 960)
  startup_stm32f40_41xxx.s: Tool: ArmAsm [4d35fa]
  compiling delay.c...
  Error: C9511E: Unable to determine the current toolkit. Check that ARM_TOOL_VARIANT is set correctly.
  Check that your license details are correct in the License Management dialog of MDK. Additional information is available at:
   - ARMLMD_LICENSE_FILE: unset
   - LM_LICENSE_FILE: unset
   - ARM_TOOL_VARIANT: unset
   - ARM_PRODUCT_PATH: unset
   - Product location: product not found
   - Toolchain location: C:\_AnZhuang\keil\Keil\ARMCCv506u7\Bin
   - Selected tool variant: mdk_lite
  Product: unknown
  Component: ARM Compiler 5.06 update 7 (build 960)
  Tool: ArmCC [4d365d]
  compiling main.c...
  Error: C9511E: Unable to determine the current toolkit. Check that ARM_TOOL_VARIANT is set correctly.
  Check that your license details are correct in the License Management dialog of MDK. Additional information is available at:
   - ARMLMD_LICENSE_FILE: unset
   - LM_LICENSE_FILE: unset
   - ARM_TOOL_VARIANT: unset
   - ARM_PRODUCT_PATH: unset
   - Product location: product not found
   - Toolchain location: C:\_AnZhuang\keil\Keil\ARMCCv506u7\Bin
   - Selected tool variant: mdk_lite
  Product: unknown
  Component: ARM Compiler 5.06 update 7 (build 960)
  Tool: ArmCC [4d365d]
  compiling stm32f4xx_syscfg.c...
  Error: C9511E: Unable to determine the current toolkit. Check that ARM_TOOL_VARIANT is set correctly.
  Check that your license details are correct in the License Management dialog of MDK. Additional information is available at:
   - ARMLMD_LICENSE_FILE: unset
   - LM_LICENSE_FILE: unset
   - ARM_TOOL_VARIANT: unset
   - ARM_PRODUCT_PATH: unset
   - Product location: product not found
   - Toolchain location: C:\_AnZhuang\keil\Keil\ARMCCv506u7\Bin
   - Selected tool variant: mdk_lite
  Product: unknown
  Component: ARM Compiler 5.06 update 7 (build 960)
  Tool: ArmCC [4d365d]
  compiling usart.c...
  Error: C9511E: Unable to determine the current toolkit. Check that ARM_TOOL_VARIANT is set correctly.
  Check that your license details are correct in the License Management dialog of MDK. Additional information is available at:
   - ARMLMD_LICENSE_FILE: unset
   - LM_LICENSE_FILE: unset
   - ARM_TOOL_VARIANT: unset
   - ARM_PRODUCT_PATH: unset
   - Product location: product not found
   - Toolchain location: C:\_AnZhuang\keil\Keil\ARMCCv506u7\Bin
   - Selected tool variant: mdk_lite
  Product: unknown
  Component: ARM Compiler 5.06 update 7 (build 960)
  Tool: ArmCC [4d365d]
  compiling sys.c...
  Error: C9511E: Unable to determine the current toolkit. Check that ARM_TOOL_VARIANT is set correctly.
  Check that your license details are correct in the License Management dialog of MDK. Additional information is available at:
   - ARMLMD_LICENSE_FILE: unset
   - LM_LICENSE_FILE: unset
   - ARM_TOOL_VARIANT: unset
   - ARM_PRODUCT_PATH: unset
   - Product location: product not found
   - Toolchain location: C:\_AnZhuang\keil\Keil\ARMCCv506u7\Bin
   - Selected tool variant: mdk_lite
  Product: unknown
  Component: ARM Compiler 5.06 update 7 (build 960)
  Tool: ArmCC [4d365d]
  compiling stm32f4xx_rcc.c...
  Error: C9511E: Unable to determine the current toolkit. Check that ARM_TOOL_VARIANT is set correctly.
  Check that your license details are correct in the License Management dialog of MDK. Additional information is available at:
   - ARMLMD_LICENSE_FILE: unset
   - LM_LICENSE_FILE: unset
   - ARM_TOOL_VARIANT: unset
   - ARM_PRODUCT_PATH: unset
   - Product location: product not found
   - Toolchain location: C:\_AnZhuang\keil\Keil\ARMCCv506u7\Bin
   - Selected tool variant: mdk_lite
  Product: unknown
  Component: ARM Compiler 5.06 update 7 (build 960)
  Tool: ArmCC [4d365d]
  compiling stm32f4xx_usart.c...
  Error: C9511E: Unable to determine the current toolkit. Check that ARM_TOOL_VARIANT is set correctly.
  Check that your license details are correct in the License Management dialog of MDK. Additional information is available at:
   - ARMLMD_LICENSE_FILE: unset
   - LM_LICENSE_FILE: unset
   - ARM_TOOL_VARIANT: unset
   - ARM_PRODUCT_PATH: unset
   - Product location: product not found
   - Toolchain location: C:\_AnZhuang\keil\Keil\ARMCCv506u7\Bin
   - Selected tool variant: mdk_lite
  Product: unknown
  Component: ARM Compiler 5.06 update 7 (build 960)
  Tool: ArmCC [4d365d]
  compiling led.c...
  Error: C9511E: Unable to determine the current toolkit. Check that ARM_TOOL_VARIANT is set correctly.
  Check that your license details are correct in the License Management dialog of MDK. Additional information is available at:
   - ARMLMD_LICENSE_FILE: unset
   - LM_LICENSE_FILE: unset
   - ARM_TOOL_VARIANT: unset
   - ARM_PRODUCT_PATH: unset
   - Product location: product not found
   - Toolchain location: C:\_AnZhuang\keil\Keil\ARMCCv506u7\Bin
   - Selected tool variant: mdk_lite
  Product: unknown
  Component: ARM Compiler 5.06 update 7 (build 960)
  Tool: ArmCC [4d365d]
  compiling misc.c...
  Error: C9511E: Unable to determine the current toolkit. Check that ARM_TOOL_VARIANT is set correctly.
  Check that your license details are correct in the License Management dialog of MDK. Additional information is available at:
   - ARMLMD_LICENSE_FILE: unset
   - LM_LICENSE_FILE: unset
   - ARM_TOOL_VARIANT: unset
   - ARM_PRODUCT_PATH: unset
   - Product location: product not found
   - Toolchain location: C:\_AnZhuang\keil\Keil\ARMCCv506u7\Bin
   - Selected tool variant: mdk_lite
  Product: unknown
  Component: ARM Compiler 5.06 update 7 (build 960)
  Tool: ArmCC [4d365d]
  compiling system_stm32f4xx.c...
  Error: C9511E: Unable to determine the current toolkit. Check that ARM_TOOL_VARIANT is set correctly.
  Check that your license details are correct in the License Management dialog of MDK. Additional information is available at:
   If you need further help, provide this complete error report to your supplier
   - ARMLMD_LICENSE_FILE: unset
   - LM_LICENSE_FILE: unset
   - ARM_TOOL_VARIANT: unset
   - ARM_PRODUCT_PATH: unset
   - Product location: product not found
   - Toolchain location: C:\_AnZhuang\keil\Keil\ARMCCv506u7\Bin
   - Selected tool variant: mdk_lite
  Product: unknown
  Component: ARM Compiler 5.06 update 7 (build 960)
  Tool: ArmCC [4d365d]
  compiling stm32f4xx_gpio.c...
  Error: C9511E: Unable to determine the current toolkit. Check that ARM_TOOL_VARIANT is set correctly.
  Check that your license details are correct in the License Management dialog of MDK. Additional information is available at:
   If you need further help, provide this complete error report to your supplier
   - ARMLMD_LICENSE_FILE: unset
   - LM_LICENSE_FILE: unset
   - ARM_TOOL_VARIANT: unset
   - ARM_PRODUCT_PATH: unset
   - Product location: product not found
   - Toolchain location: C:\_AnZhuang\keil\Keil\ARMCCv506u7\Bin
   - Selected tool variant: mdk_lite
  Product: unknown
  Component: ARM Compiler 5.06 update 7 (build 960)
  Tool: ArmCC [4d365d]
  compiling stm32f4xx_it.c...
  Error: C9511E: Unable to determine the current toolkit. Check that ARM_TOOL_VARIANT is set correctly.
  Check that your license details are correct in the License Management dialog of MDK. Additional information is available at:
   If you need further help, provide this complete error report to your supplier
   - ARMLMD_LICENSE_FILE: unset
   - LM_LICENSE_FILE: unset
   - ARM_TOOL_VARIANT: unset
   - ARM_PRODUCT_PATH: unset
   - Product location: product not found
   - Toolchain location: C:\_AnZhuang\keil\Keil\ARMCCv506u7\Bin
   - Selected tool variant: mdk_lite
  Product: unknown
  Component: ARM Compiler 5.06 update 7 (build 960)
  Tool: ArmCC [4d365d]
  &quot;..\OBJ\LED.axf&quot; - 13 Error(s), 0 Warning(s).
  Target not created.
  Build Time Elapsed:  00:00:01
  </code></pre>
  <p>form the build output it means the keil license is incorrent.But I've tried every type license code which are generated by the keygen and all of these license are faild.</p>
  <p>so, is there anybody have the same issue as mine? and any solutions or advices to try?
  many thanks.</p>