[O] Problems Setting Properties

[Edward Guyatt]

Hello,

When I try to set a property in my planner file (15005 lines to go wrong 
:P), I get an error message. Here is the backtrace from saying C-c C-x p 
(org-set-property) on any heading.

Debugger entered--Lisp error: (wrong-type-argument integer-or-marker-p nil)
  org-buffer-property-keys(nil t t)
  org-read-property-name()
  org-set-property(nil nil)
  call-interactively(org-set-property nil nil)
  command-execute(org-set-property)

I get the same result saying C-c C-c s at a property drawer.

I have tried to narrow it down to a specific point by deleting big 
parts. I couldn't narrow it down: if I deleted some parts it would 
behave normally and if I deleted parts containing said parts it would 
give the error.

I've only experienced this recently after upgrading from Debian Wheezy 
to Jessie, so from org-mode 7.8.11-1 to 8.2.10-1.

Thanks in advance,

Ed