Verify/Compile errors on even the simplest sketch

I have recently returned to try to experiment with Arduino but obviously have some setup issues as even the simplest possible sketch (Bareminimum) gives error messages on verify/compile.

I am using Windows 10 64 bit.
I have installed IDE 1.8.5 from Windows store 1.8.10.0

Compiling without verbose output I see the following :

Arduino: 1.8.5 (Windows Store 1.8.10.0) (Windows 10), Board: "Arduino/Genuino Uno"

c:/program files/windowsapps/arduinollc.arduinoide_1.8.10.0_x86__mdqgnx93n4wtt/hardware/tools/avr/bin/../lib/gcc/avr/4.9.2/../../../../avr/lib/avr5/crtatmega328p.o:(.init9+0x0): undefined reference to `main'

collect2.exe: error: ld returned 1 exit status

exit status 1

Error compiling for board Arduino/Genuino Uno.

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

===================================

After enabling verbose output I get:

Arduino: 1.8.5 (Windows Store 1.8.10.0) (Windows 10), Board: "Arduino/Genuino Uno"

C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\arduino-builder -dump-prefs -logger=machine -hardware C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware -tools C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\tools-builder -tools C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\tools\avr -built-in-libraries C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\libraries -libraries C:\Users\jimbo\Dropbox__Jimsdata_Electronics_Etc\Arduino_Sketches\libraries -fqbn=arduino:avr:uno -ide-version=10805 -build-path C:\Users\jimbo\AppData\Local\Temp\arduino_build_432175 -warnings=default -build-cache C:\Users\jimbo\AppData\Local\Temp\arduino_cache_203705 -prefs=build.warn_data_percentage=75 -prefs=runtime.tools.arduinoOTA.path=C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\tools\avr -prefs=runtime.tools.avr-gcc.path=C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\tools\avr -prefs=runtime.tools.avrdude.path=C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\tools\avr -verbose C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\examples\01.Basics\BareMinimum\BareMinimum.ino

C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\arduino-builder -compile -logger=machine -hardware C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware -tools C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\tools-builder -tools C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\tools\avr -built-in-libraries C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\libraries -libraries C:\Users\jimbo\Dropbox__Jimsdata_Electronics_Etc\Arduino_Sketches\libraries -fqbn=arduino:avr:uno -ide-version=10805 -build-path C:\Users\jimbo\AppData\Local\Temp\arduino_build_432175 -warnings=default -build-cache C:\Users\jimbo\AppData\Local\Temp\arduino_cache_203705 -prefs=build.warn_data_percentage=75 -prefs=runtime.tools.arduinoOTA.path=C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\tools\avr -prefs=runtime.tools.avr-gcc.path=C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\tools\avr -prefs=runtime.tools.avrdude.path=C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\tools\avr -verbose C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\examples\01.Basics\BareMinimum\BareMinimum.ino
Using board 'uno' from platform in folder: C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\arduino\avr
Using core 'arduino' from platform in folder: C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\arduino\avr
Detecting libraries used...
"C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\tools\avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -flto -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10805 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR "-IC:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\arduino\avr\cores\arduino" "-IC:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\arduino\avr\variants\standard" "C:\Users\jimbo\AppData\Local\Temp\arduino_build_432175\sketch\BareMinimum.ino.cpp" -o "nul"
Generating function prototypes...
"C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\tools\avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -flto -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10805 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR "-IC:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\arduino\avr\cores\arduino" "-IC:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\arduino\avr\variants\standard" "C:\Users\jimbo\AppData\Local\Temp\arduino_build_432175\sketch\BareMinimum.ino.cpp" -o "C:\Users\jimbo\AppData\Local\Temp\arduino_build_432175\preproc\ctags_target_for_gcc_minus_e.cpp"
"C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\tools-builder\ctags\5.8-arduino11/ctags" -u --language-force=c++ -f - --c++-kinds=svpf --fields=KSTtzns --line-directives "C:\Users\jimbo\AppData\Local\Temp\arduino_build_432175\preproc\ctags_target_for_gcc_minus_e.cpp"
Compiling sketch...
"C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\tools\avr/bin/avr-g++" -c -g -Os -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -MMD -flto -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10805 -DARDUINO_AVR_UNO -DARDUINO_ARCH_AVR "-IC:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\arduino\avr\cores\arduino" "-IC:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\arduino\avr\variants\standard" "C:\Users\jimbo\AppData\Local\Temp\arduino_build_432175\sketch\BareMinimum.ino.cpp" -o "C:\Users\jimbo\AppData\Local\Temp\arduino_build_432175\sketch\BareMinimum.ino.cpp.o"
Compiling libraries...
Compiling core...
Using precompiled core
Linking everything together...
"C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\tools\avr/bin/avr-gcc" -Os -g -flto -fuse-linker-plugin -Wl,--gc-sections -mmcu=atmega328p -o "C:\Users\jimbo\AppData\Local\Temp\arduino_build_432175/BareMinimum.ino.elf" "C:\Users\jimbo\AppData\Local\Temp\arduino_build_432175\sketch\BareMinimum.ino.cpp.o" "C:\Users\jimbo\AppData\Local\Temp\arduino_build_432175/..\arduino_cache_203705\core\core_arduino_avr_uno_a94ab6aaf61dfb93b4a8079c694a14c2.a" "-LC:\Users\jimbo\AppData\Local\Temp\arduino_build_432175" -lm
c:/program files/windowsapps/arduinollc.arduinoide_1.8.10.0_x86__mdqgnx93n4wtt/hardware/tools/avr/bin/../lib/gcc/avr/4.9.2/../../../../avr/lib/avr5/crtatmega328p.o:(.init9+0x0): undefined reference to `main'

collect2.exe: error: ld returned 1 exit status

exit status 1
Error compiling for board Arduino/Genuino Uno.

=====================================
I would appreciate assistance to determine what errors in my setup are causing this and how to correct those errors.

Thanks jb

Try closing all Arduino IDE windows and then start the Arduino IDE again. That should clear the cache, which hopefully will solve the problem.

Thank you - that enable a clean verify compile.

Cheers jb