Arduino Mini not working any more

I have stuff that used to compile and work but now does not. This is using the Pro Micro, but now the only board option is the "Arduino Micro (USB). When I try and use it I get this group of warnings:-

WARNING: Category '' in library EEPROM is not valid. Setting to 'Uncategorized'
WARNING: Category '' in library SPI is not valid. Setting to 'Uncategorized'
WARNING: Category '' in library SoftwareSerial is not valid. Setting to 'Uncategorized'
WARNING: Category '' in library Wire is not valid. Setting to 'Uncategorized'
Warning: platform.txt from core 'Leonardo & Micro MIDI-USB (arcore)' contains deprecated recipe.ar.pattern="{compiler.path}{compiler.ar.cmd}" {compiler.ar.flags} {compiler.ar.extra_flags} "{build.path}/{archive_file}" "{object_file}", automatically converted to recipe.ar.pattern="{compiler.path}{compiler.ar.cmd}" {compiler.ar.flags} {compiler.ar.extra_flags} "{archive_file_path}" "{object_file}". Consider upgrading this core.
Detecting libraries used...

Then the MIDIUSB libiary gives the error:-

void recieveSysEx(midiEventPacket_t sx){
                   ^
FILE NAME REPLACED :426:19: error: 'midiEventPacket_t' was not declared in this scope

Resulting in lots of errors resulting from this.

I am using the 1.0.4 version of the MIDIUSB libiary.

Anyone know what is going on?

Where did you get this "Leonardo & Micro MIDI-USB (arcore)" core from? The one in the Adafruit boards package has a board named "Arduino Micro (MIDI)", but no board named "Arduino Micro (USB)". The original core has a board named "Arduino Micro (arcore)", but no board named "Arduino Micro (USB)".

Thanks for the reply pert.

Where did you get this "Leonardo & Micro MIDI-USB (arcore)" core from?

Not sure about that. I download all sorts of stuff trying to recreate the problems around here.

I did solve my problem by choosing the "Arduino/Genuino Micro" board from the tools menu. The Micro is such a poor name and my dyslexia keeps mixing it up with the mini, so much so I don't actually see the "Arduino/Genuino Micro" entry. I managed to see it this time round and choosing it made my stuff recompile again so that is a relief.

I'm glad to hear you got it working! It's probably way better if you can use the Arduino/Genuino Micro board from Arduino AVR Boards, since the arcore core is very outdated (as demonstrated by those warnings) and unmaintained.