Loading maps saved with DeluxePaint "Stencil" feature active crashes the game
From Worms Knowledge Base
DeluxePaint, or DPaint, was a very popular graphics editing tool developed by Electronic Arts for the Amiga (and, up until DPaint II, for MS-DOS). It was used to create the graphics for many games on the Amiga, SNES, MegaDrive and MS-DOS. In fact some of the maps created for use in Worms United were made in DeluxePaint. It's not as powerful as, say, PhotoShop or Paint Shop Pro, but it is very good for pixel-specific work as opposed to touching up photos.
DPaint's popularity was likely because of an Amiga 500 entertainment bundle, "Cartoon Capers", that included DeluxePaint III alongside a variety of cartoon-themed games. The most popular version of DPaint is DeluxePaint IV AGA, which is optimized for working with the AGA chipset included in the A1200, A4000, A4000T and CD32 systems. The last version of the application, DeluxePaint V, was Electronic Arts' last non-game release, published nine years after the first DPaint.
The Stencil Feature
So if, for example, you have a 4-colour image, you can set up a stencil to allow you to make changes to pixels of colours 00, 01 and 03, but leave pixels of colour 02 intact.
Conflict with Worms / WormsDC
DPaint leaves a flag in an IFF file to store whether or not a Stencil is in use when the file was saved. Unfortunately this causes a conflict within both Worms and WormsDC when they try to open the files. With colour maps (and Graffiti maps in WormsDC) this causes the game to crash when the corresponding map is loaded. WormsDC is also unable to read Mountain sets and DIY landscapes that were created from source files where the Stencil feature was activated.