I have submitted this as one of the "Top 3 Bugs To Be Fixed" when they did a call out to the community for requests several months ago.
http://forum.thegamecreators.com/?m=forum_view&b=1&t=193289&p=0
It was chosen, and is currently listed as #16 on the list.
Workaround:
I have a workaround that might not work for everyone.
1. Consider the "locked" image to be "Image A".
2. Copy an area of screen the exact dimensions of "Image A" to a new image, "Image B".
3. Paste "Image A" to this space on the screen.
4. Copy what you just pasted to a new image, "Image C".
5. Paste "Image B" back in place to cover up any on screen evidence.
You now have "Image C" unlocked with "Image A" contents. Basically you copy the contents of your image to a new separate image by way of pasting/screen grabbing and covering up the mess.
You might ask why not simply copy "Image A" to "Image C"?
Most if not all methods and plugins crash or fail due to the image being locked.
Covering up the on-screen effect is 99.9999% effective. If the screen contents are rapidly changing on that single frame following this technique the coverup might not line up with screen contents. This would never be visible with a typical game even at low frame rate.
If anyone has a more efficient method, I would be happy to hear it. I wouldn't be surprised if one existed.
Further:
I don't know what it is you are trying to ultimately do, but you might be able to use Image Kit v2 in some way to achieve your ultimate goal I suspect. Image Kit will still have this problem and a direct approach will not work. I was able to use Image kit to get around this problem when it was combined with a custom shader.
Reference:
http://forum.thegamecreators.com/?m=forum_view&t=184514&b=1
