You cannot export layers, within Pencil2D. But you can save your project and then open a new or existing project, and then import layers, into this project.
Use File, then Import Layer, specified project name, that’s a .PCLX file and then you’ll be asked to specify the layer or layers, that you wish to import.
Using Pencil2D version 0 6.6 your next step is to save the project. I suggest that if the project you loaded was Mouse-6.pclx, that you save the new file as Mouse-7.pclx.
Once you have saved the project, select the Camera Layer, on the first defined frame, on that layer ie 1 I’d the layers you have imported and the imported images are available. You can import. vec, .wav, .mp3, .mp4 pictures layers and .mp4 sound layers.
Sometimes when you perform Layer imports with Pencil2D version 0.6.6 it crashes!
You can however save individual bitmapped frames as .png files or a sequence of bitmapped frames as .png files. These can then be loaded into a bitmapped layer, within another project in Pencil2D.
The program crashes because you’re hitting an assertion, which is only possible in debug builds.
In a distributed release build, you will get an error but the program won’t crash.
As for the error you’re getting, it looks like you messed up the extension.
In the future please confirm whether the bug can reproduced in the nightly build before making a report on it.
Bug reports should be based on either our stable or nightly builds, compiling the program on your own can lead to various confusing situations, such as what you’ve experienced