The ILLiad DOI Resolver DSP Addon will throw the following error message in the logs when attempting to handle null Month field values:

ERROR AtlasSystems.Scripting.LuaApi.SystemScriptEnvironment - An addon script error has occurred in a system script. The following error message was returned: A Lua script error has occurred.

Bug# 17004

The CCC Get It Now DSP addon encounters the following errors when attempting to obtain the ISSN:

-DEBUG AtlasSystems.Scripting.DataObjects.ScriptIndexedObjectWrapper - Attempting to get the value of ISSN on an object of type Transaction
-DEBUG AtlasSystems.Scripting.DataObjects.ScriptIndexedObjectWrapper - Value obtained: NULL

ILLiad v9.2

Bug# 16572

Certain kinds of server addons may experience an issue where errors are not logged. INFO and DEBUG entries for the addon will still log properly.

Bug #16386

There is an issue causing version 2.1.0 of the Google Search addon to pull up a blank, white screen, and disable the addon's buttons.

Bug# 13090

In some cases, an error response from the NCIP server is not handled properly by the addon. The NCIP message validation and error handling should be improved to handle these cases.

Bug# 12033

Special characters/diacritics in the Author or Title field of a transaction will break the search for the Get It Now addon. The characters appear as they should in the client, and the URL works outside of ILLiad, but when left in the fields the search breaks. Once the characters are removed/replaced it works fine.

Bug# 7600

If a system addon is created but FormNames are also entered, the addon will be loaded for both the system script environment and for each form script environment that is specified. An example where this causes errors is when registering system event handlers which can only be registered to a single addon.
 
Forms are not relevent in Library, System, or Server addons.