(wrong-type-argument stringp nil) in org-agenda skip

[colonelpanic8]

Looks like something may have changed in org-mode that is breaking our category integration. Haven't had time to look in to it yet.

Debugger entered--Lisp error: (wrong-type-argument stringp nil)
  looking-at(nil)
  org-agenda-skip()
  org-scan-tags(#f(compiled-function () #<bytecode 0x2202d49>) t nil nil)
  org-map-entries(#f(compiled-function () #<bytecode 0x2202d49>) nil nil #f(compiled-function () #<bytecode 0x2202d61>))
  occ-get-value-by-category(:get-category-from-element org-projectile-get-category-from-heading)
  apply(occ-get-value-by-category (:get-category-from-element org-projectile-get-category-from-heading))
  occ-get-value-by-category-from-filepath("~/org/projects.org" :get-category-from-element org-projectile-get-category-from-heading)
  apply(occ-get-value-by-category-from-filepath ("~/org/projects.org" :get-category-from-element org-projectile-get-category-from-heading))
  occ-get-categories-from-filepath("~/org/projects.org" :get-category-from-element org-projectile-get-category-from-heading)
  #f(compiled-function (s) #<bytecode 0x190e5ed>)(#<org-projectile-single-file-strategy org-projectile-single-file-strategy>)
  apply(#f(compiled-function (s) #<bytecode 0x190e5ed>) #<org-projectile-single-file-strategy org-projectile-single-file-strategy>)
  #f(compiled-function (cl-cnm s) #<bytecode 0x190ea79>)(#f(compiled-function (&rest cnm-args) #<bytecode 0x2202b29>) #<org-projectile-single-file-strategy org-projectile-single-file-strategy>)
  apply(#f(compiled-function (cl-cnm s) #<bytecode 0x190ea79>) #f(compiled-function (&rest cnm-args) #<bytecode 0x2202b29>) #<org-projectile-single-file-strategy org-projectile-single-file-strategy>)
  #f(compiled-function (&rest args) #<bytecode 0x1ae5981>)(#<org-projectile-single-file-strategy org-projectile-single-file-strategy>)
  apply(#f(compiled-function (&rest args) #<bytecode 0x1ae5981>) #<org-projectile-single-file-strategy org-projectile-single-file-strategy> nil)
  occ-get-categories(#<org-projectile-single-file-strategy org-projectile-single-file-strategy>)
  org-projectile-helm-source(nil)
  org-projectile-helm-template-or-project(nil)
  funcall-interactively(org-projectile-helm-template-or-project nil)
  call-interactively(org-projectile-helm-template-or-project nil nil)
  command-execute(org-projectile-helm-template-or-project)