Puzzling loss of ability to compile for Pro Micro

After having upgraded the Arduino IDE from 1.6.x to the current version (1.8.5), I found that the SparkFun addon boards had disappeared from the Boards drop-down. I went to the Boards Manager, and though the SF links were still there, the AVRs did not show as being installed. I installed as usual, after double-checking the github URL with the Hookup guide and observing that the repository appeared to be active quite recently. The boards duly appeared in the Boards drop-down after rebooting the IDE, as expected. However, no sketch will compile (Verify) for Pro Micro. As I’m not trying to Upload, I don’t think there can be any hardware problem. Below are links to snips of the Board Manager after installing SF AVR, and the IDE with the error message generated when trying to Verify the IDE Basic Example “Blink”. I also include the IDE error messages here as “code”:

Arduino: 1.8.5 (Windows 7), Board: "SparkFun Pro Micro, ATmega32U4 (5V, 16 MHz)"

Board promicro (platform avr, package SparkFun) is unknown

Error compiling for board SparkFun Pro Micro.

I have to wonder if the IDE has changed how addons are handled, as there does not appear to be a hardware folder inside the Arduino sketch folder any more. Any ideas? My sketch folder IS a Dropbox, if that might factor in somehow…

https://www.dropbox.com/s/jox0w3bm2dwou … d.JPG?dl=0

https://www.dropbox.com/s/0093cfq1dekkr … o.JPG?dl=0

OK, no replies from the community, but I solved it for myself eventually using the usual graduated steps of IDE deconstruction and reconstruction. I will briefly describe how I fixed the problem in case anyone else finds their way here with the same issue.

Uninstalling the IDE and re-installing didn’t help (neither did deinstalling and reinstalling the SF AVR board defs through the Board Manager). I concluded that it was a corrupted file among those not routinely replaced when installing the IDE. These can be tracked down using he same Preference panel used to associate the Boards Managers. Just below the BM line the IDE helpfully tells you where to go to hand-edit your Preferences file. There will be many other files in this folder, including the .json files defining additional boards. I deleted the entire folder, …\Arduino 15 in my case. It was not necessary to thereafter reinstall the IDE, just restarting it, navigating to the Board Manager and reinstalling the vanished SF AVR .json did the trick. Naturally I had to similarly reinstall all the other aftermarket board defs, but helpfully most of the IDE settings were not in that file, so the Board Manager still had all the URLs handy, and the other choices (such as Sketchbook location) were unaffected. it does make one wonder where those live, if not in the indicated preferences.txt file. A mystery for another day.

I had the same problem with my arduino IDE and sparkfun pro micro board and was struggling since last 3 days and to over come this situation , read tons of solutions on the internet but all not helpful ONLY YOUR research is HELPFUL…many many thanks to you… :sunglasses: :sunglasses: :sunglasses: :sunglasses: :sunglasses: :sunglasses: :sunglasses: