SOLVED: I imported a jpeg map and added masks and walls, now it is locked

I create a map by importing a jpeg, I added masks and wall to the map and now I cannot export it as it is showing the padlock and will not let me export it.

OS: Fedora 28
Java:
java version "1.8.0_161"
Java(TM) SE Runtime Environment (build 1.8.0_161-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.161-b12, mixed mode)

 

Ah I solved it - I had placed Langston on the map for testing the lighting and I had saved it with him on there. This causes the map to be locked. Simply removing him from the map removes the lock icon and it is now exportable.

Phew - thought I'd lost my masking work

 

An example PC that seemed to come with the 5E Players Handbook ruleset