Problem: I have Null folder names for folders that don't exist.
Answer: Hit "edit" and delete those folders. (This should be gone as of categories v2.99).
Problem: Categories is not removing apps in v2.28. They are duplicates now! (fixed in v2.29)
Answer: Use the hidden icons section and hide them. After this, check and see if categories auto hides apps on its own.
Problem: I have folders that I cant edit or delete. They don't show up.
Answer: Your conversion from 2.26 to 2.29 update errored out somewhere. We hoped this was solved in v2.99 or newer, but you need to manually delete those folders from /Applications folder using SSH or a program like iFile or such. Then you can just recreate them. If you don't know how to delete the folders using iFile, then you can try just hiding them using the "hidden Icons" section so you don't have to see them and make new ones with slightly different names.
Problem: I have folders I made with an older version of categories. They have a weird character or space in the name. I cant edit them or change the icon. What now?
Answer: This requires using the iFile method as described above. New folders can be created with spaces and weird names as of Categories 2.29 without issue. It's only folders created with a *previous* version that have this problem.
Problem: I made a folder and it no longer asks me for an icon. This sucks!
Answer: Loading icon screen is very memory intensive. Therefore we no longer do this by default anymore. You can hit "edit" and then tap the folder and change the icon though. We are in progress of adding a paged icon selector screen that is low on memory.
Problem: In the new interface, where is the "Add" button? I can't add new folders!
Answer: In "Manage Folders", use "Edit" then "Add" shows up.
Problem: I put the categories app into a folder. How do I load it?
Answer: Use Spotlight
Problem: I have duplicate icons now on springboard and in folders. Why are there duplicates? What now?
Answer: There are not duplicates. Categories hides apps as it adds them to folders. I am not sure what went wrong, but just use the "Hidden Icons" option and hide the icons you don't want visible.
Problem: I used the "Hidden Icons" option and now there are duplicates on my springboard of applications also in folders. Why are there duplicates? What now?
Answer: (See above solution).
Problem: I can't add my webclips to a folder. They just don't show up.
Answer: Webclips are not apps. This is not yet supported. It's actually a fairly complicated problem to solve and being worked on.
For other issues not handled by above, you can contact me via my email address located in Cydia.
BigBoss