Handle errors due to a save being incompatible with the new version

[BlackRam-oss]

Your save may become incompatible or give errors from a game release for the following reasons:

• The save was performed while running a label that has been deleted or renamed.
• The save was performed when there was a custom element in the canvas, but it was removed or renamed from one version to another.
• The player saved in a label where a step was changed, removed, or added before the current step.