Example sketches not compiling

Hi everyone

Been a long time since I did any arduino stuff but today I went to load a sketch and nothing will compile, not even the examples. I have downloaded the latest version but still no luck. I don't have a good enough understanding to translate the error message below. Any guidance gratefully received. TIA

Arduino: 1.6.7 (Mac OS X), TD: 1.27, Board: "Arduino Uno"

failed MSpanList_Insert 0x308000 0x10ae586d4b0f4 0x0
fatal error: MSpanList_Insert

runtime stack:
runtime.throw(0x2a950b)
/usr/local/go/src/runtime/panic.go:491 +0xad fp=0x7ffeefbff3d0 sp=0x7ffeefbff3a0
runtime.MSpanList_Insert(0x2c7028, 0x308000)
/usr/local/go/src/runtime/mheap.c:692 +0x8f fp=0x7ffeefbff3f8 sp=0x7ffeefbff3d0
MHeap_FreeSpanLocked(0x2c3c20, 0x308000, 0x100)
/usr/local/go/src/runtime/mheap.c:583 +0x163 fp=0x7ffeefbff438 sp=0x7ffeefbff3f8
MHeap_Grow(0x2c3c20, 0x8, 0x0)
/usr/local/go/src/runtime/mheap.c:420 +0x1a8 fp=0x7ffeefbff478 sp=0x7ffeefbff438
MHeap_AllocSpanLocked(0x2c3c20, 0x1, 0x0)
/usr/local/go/src/runtime/mheap.c:298 +0x365 fp=0x7ffeefbff4b8 sp=0x7ffeefbff478
mheap_alloc(0x2c3c20, 0x1, 0x12, 0x0)
/usr/local/go/src/runtime/mheap.c:190 +0x121 fp=0x7ffeefbff4e0 sp=0x7ffeefbff4b8
runtime.MHeap_Alloc(0x2c3c20, 0x1, 0x10000000012, 0x10219)
/usr/local/go/src/runtime/mheap.c:240 +0x66 fp=0x7ffeefbff518 sp=0x7ffeefbff4e0
MCentral_Grow(0x2cb998, 0x0)
/usr/local/go/src/runtime/mcentral.c:197 +0x8b fp=0x7ffeefbff580 sp=0x7ffeefbff518
runtime.MCentral_CacheSpan(0x2cb998, 0x0)
/usr/local/go/src/runtime/mcentral.c:85 +0x167 fp=0x7ffeefbff5b8 sp=0x7ffeefbff580
runtime.MCache_Refill(0x304000, 0x12, 0x0)
/usr/local/go/src/runtime/mcache.c:90 +0xa0 fp=0x7ffeefbff5e0 sp=0x7ffeefbff5b8
runtime.mcacheRefill_m()
/usr/local/go/src/runtime/malloc.c:368 +0x57 fp=0x7ffeefbff600 sp=0x7ffeefbff5e0
runtime.onM(0x221810)
/usr/local/go/src/runtime/asm_amd64.s:273 +0x9a fp=0x7ffeefbff608 sp=0x7ffeefbff600
runtime.mallocgc(0x120, 0x1bd640, 0x0, 0x0)
/usr/local/go/src/runtime/malloc.go:178 +0x849 fp=0x7ffeefbff6b8 sp=0x7ffeefbff608
runtime.newobject(0x1bd640, 0x304000)
/usr/local/go/src/runtime/malloc.go:353 +0x49 fp=0x7ffeefbff6e0 sp=0x7ffeefbff6b8
runtime.newG(0x27daa)
/usr/local/go/src/runtime/proc.go:233 +0x2a fp=0x7ffeefbff6f8 sp=0x7ffeefbff6e0
allocg(0x2b65e0)
/usr/local/go/src/runtime/proc.c:925 +0x1f fp=0x7ffeefbff708 sp=0x7ffeefbff6f8
runtime.malg(0x8000, 0x2b6680)
/usr/local/go/src/runtime/proc.c:2106 +0x1f fp=0x7ffeefbff738 sp=0x7ffeefbff708
runtime.mpreinit(0x2b6a40)
/usr/local/go/src/runtime/os_darwin.c:137 +0x27 fp=0x7ffeefbff750 sp=0x7ffeefbff738
mcommoninit(0x2b6a40)
/usr/local/go/src/runtime/proc.c:201 +0xc9 fp=0x7ffeefbff778 sp=0x7ffeefbff750
runtime.schedinit()
/usr/local/go/src/runtime/proc.c:138 +0x55 fp=0x7ffeefbff7a0 sp=0x7ffeefbff778
runtime.rt0_go(0x7ffeefbff7d8, 0x1a, 0x7ffeefbff7d8, 0x0, 0x0, 0x1a, 0x7ffeefbff9b0, 0x7ffeefbff9e8, 0x7ffeefbff9f4, 0x7ffeefbffa04, ...)
/usr/local/go/src/runtime/asm_amd64.s:95 +0x116 fp=0x7ffeefbff7a8 sp=0x7ffeefbff7a0
arduino-builder returned 2

Error compiling.

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

Im using MacOS 10.13.6

Which is an upgrade since last using Arduino if that could be an issue.

The problem is that you are using a very old version of the Arduino IDE with a newer version of macOS. Please update to the latest version of the Arduino IDE, available here:

Perfect. I thought I had updated it but was opening the wrong version. Thanks very much.