Bugs that deserve immediate attention because the results of them are especially ugly:
jAlbum allows a user to name a folder slides or thumbs, which produces bizarre results in a project.
If a user chooses "..." as the image bounds, but doesn't enter any values, then hits OK, there's a console error dump, and Make Album won't work. If the user then chooses another skin, he gets a popup error dump. This should be handled more gracefully, perhaps by returning to the previously-selected bounds when no values are entered.
The FixedShapeFilter produces images in the same aspect ratio (as it should), but not always of the same size. For thumbnails, the result is, bizarrely, dependent upon the slide image bounds. This has started producing actual display errors in newer skins, which often use larger thumbnail image bounds. For slide images, there is almost no way to produce images that are all the same size, even if the originals are much larger than the slide image bounds. See: https://jalbum.net/forum/thread.jspa?threadID=49192
Bugs that produce errors or unexpected results, but that aren't often encountered:
Changing the default file naming from index and .html doesn't clear out the older files - you end up with, for example, both index.html and index.php. Uploading both index.html and index.php could produce some very puzzling results, depending upon server configuration.
Selecting or de-selecting the video icon doesn't produce new thumbnails with Make Album - the user has to force a Make All.
If project loading is slow, the user can "beat it to the punch," and get to the settings panels before the project is loaded, resulting in random default values rather than the saved project values. Haven't seen reports of this one in a while, and it may be limited to BluPlusPlus. This is rare but nasty, because the results can be a mess, and difficult to recover from if the user doesn't have good backups. Some basic thread-locking in the loader should cure it. See: https://jalbum.net/forum/thread.jspa?threadID=49640.
File selector for webLocation representing images doesn't remember location.
After deletion of a user-installed skin, and notification that the bundled version is still present, the skin doesn't reload. The settings tabs from the deleted version remain.
Changing skin or jAlbum settings that should trigger a change in the theme image crop mask don't trigger the change until the user closes the settings panel or clicks Make Album. That means that the theme image crop focus panel isn't always getting updated when it should be.
Audio file with related THM, plus Link to originals, does not produce a slide image (OK for similar video situation).
jAlbum installer for Windows doesn't grab focus, so it's hidden under the File Explorer window from which the user has launched it. Confusing for users.
In macOS, opening the skin editor, choosing File, Open, then trying to quit the application produces a "hang," and jAlbum must be force-quit. Easily reproducible, but unlikely that a user would encounter it.