Problem compiling in 1.6.7, worked in 1.6.6

Hi - my first post here and I'm not really an Arduino hobbyist, just want to make a couple of projects.

I compiled and uploaded a simple sketch (to detect if a car engine is running from battery voltage) in 1.6.6 and successfully uploaded it to my Uno - no problems and it all works.

When I tried to upload the sketch to a Nano, I think I had a driver problem - said 'not in sync' or something. I couldn't solve that by updating drivers etc, so I installed 1.6.7.

Now the sketch won't compile. I'm using 1.6.7 under Windows 10 64 bit. The error message is as follows:

(BTW - the result is just the same if I try and compile 'BareMinimum' from the examples library)

open C:\Users\John\AppData\Local\Temp\build1b4f60508f459ca967c88c057b1fe536.tmp\preproc\ctags_target_for_gcc_minus_e.cpp: The system cannot find the file specified.

Here is my verbose output from the compile attempt:

Arduino: 1.6.7 (Windows 10), Board: "Arduino Nano, ATmega328"

C:\Program Files (x86)\Arduino\arduino-builder -dump-prefs -logger=machine -hardware "C:\Program Files (x86)\Arduino\hardware" -tools "C:\Program Files (x86)\Arduino\tools-builder" -tools "C:\Program Files (x86)\Arduino\hardware\tools\avr" -built-in-libraries "C:\Program Files (x86)\Arduino\libraries" -libraries "C:\Users\John\Documents\Arduino\libraries" -fqbn=arduino:avr:nano:cpu=atmega328 -ide-version=10607 -build-path "C:\Users\John\AppData\Local\Temp\build1b4f60508f459ca967c88c057b1fe536.tmp" -warnings=none -prefs=build.warn_data_percentage=75 -verbose "C:\Users\John\Documents\Arduino\Sketches\voltage_switch.txt\voltage_switch.txt.ino" C:\Program Files (x86)\Arduino\arduino-builder -compile -logger=machine -hardware "C:\Program Files (x86)\Arduino\hardware" -tools "C:\Program Files (x86)\Arduino\tools-builder" -tools "C:\Program Files (x86)\Arduino\hardware\tools\avr" -built-in-libraries "C:\Program Files (x86)\Arduino\libraries" -libraries "C:\Users\John\Documents\Arduino\libraries" -fqbn=arduino:avr:nano:cpu=atmega328 -ide-version=10607 -build-path "C:\Users\John\AppData\Local\Temp\build1b4f60508f459ca967c88c057b1fe536.tmp" -warnings=none -prefs=build.warn_data_percentage=75 -verbose "C:\Users\John\Documents\Arduino\Sketches\voltage_switch.txt\voltage_switch.txt.ino" Build options changed, rebuilding all "C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10607 -DARDUINO_AVR_NANO -DARDUINO_ARCH_AVR "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino" "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\variants\eightanaloginputs" "C:\Users\John\AppData\Local\Temp\build1b4f60508f459ca967c88c057b1fe536.tmp\sketch\voltage_switch.txt.ino.cpp" "C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10607 -DARDUINO_AVR_NANO -DARDUINO_ARCH_AVR "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino" "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\variants\eightanaloginputs" "C:\Users\John\AppData\Local\Temp\build1b4f60508f459ca967c88c057b1fe536.tmp\sketch\voltage_switch.txt.ino.cpp" "C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10607 -DARDUINO_AVR_NANO -DARDUINO_ARCH_AVR "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino" "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\variants\eightanaloginputs" "C:\Users\John\AppData\Local\Temp\build1b4f60508f459ca967c88c057b1fe536.tmp\sketch\voltage_switch.txt.ino.cpp" open C:\Users\John\AppData\Local\Temp\build1b4f60508f459ca967c88c057b1fe536.tmp\preproc\ctags_target_for_gcc_minus_e.cpp: The system cannot find the file specified. Error compiling.

Any help much appreciated!

(also - any suggestions about uploading - that worked in 1.6.6 with the Uno but then failed with the Nano - I fully expect it to fail again in 1.6.7!)

Well, I’ve solved the compiling problem - downloaded 1.6.7 again and reinstalled - and, mysteriously, it worked.

But uploading didn’t. I’ll start a new topic for that.