This page attempts to be a comprehensive list of the errors that may be returned by the Bugzilla XML-RPC API and the BzAPI HTTP API proxy.
50 (Param Required)
A login or password parameter was not provided.
51 (Invalid Object)
A value was specified that does not exist in the database.
52 (Invalid XML-RPC Value)
The XML-RPC input itself is invalid e.g. you specified something like <int>a string</int>, or you tried to pass a string into a parameter that only accepts ints.
53 (Invalid Parameter)
You attempted to pass an undefined value to an internal function in Bugzilla.
100 (Invalid Bug Alias)
You specified an alias and either: (a) the Bugzilla you're querying doesn't support aliases or (b) there is no bug with that alias.
101 (Invalid Bug ID)
The bug_id you specified doesn't exist in the database.
102 (Access Denied)
You do not have access to the bug_id you specified.
103 (Invalid Alias)
You asked for a bug to be created with an alias, and the alias you specified is invalid for some reason.
104 (Invalid Field)
One of the drop-down fields has an invalid value, or a value entered in a text field is too long. (This code is retired; see code 51.)
105 (Invalid Component)
You didn't specify a component.
106 (Invalid Product)
Either you didn't specify a product, this product doesn't exist, or you don't have permission to enter bugs in this product.
107 (Invalid Summary)
You didn't specify a summary for the bug
108 (Bug Edit Denied)
You did not have the necessary rights to edit the bug.
109 (Invalid Field Name)
You specified a field that doesn't exist or isn't a drop-down field.
110 (Comment Is Private)
You specified the id of a private comment in the comment_ids argument, and you are not in the "insider group" that can see private comments.
111 (Invalid Comment ID)
You specified an id in the comment_ids argument that is invalid--either you specified something that wasn't a number, or there is no comment with that id.
112 (Invalid Bug URL)
One of the URLs you provided did not look like a valid bug URL.
113 (Can't Make Private Comments)
You tried to add a private comment, but don't have the necessary rights.
300 (Invalid Username or Password)
The username does not exist, or the password is wrong.
301 (Account Disabled)
The account has been disabled. A reason may be specified with the error.
302 (Auth: Invalid Email)
An external verification source, such as LDAP, returned an invalid email address.
304 (Authorization Required)
You are logged in, but you are not authorized to see one of the users you wanted to get information about by user id.
500 (Illegal Email Address)
This Bugzilla does not allow you to create accounts with the format of email address you specified. Account creation may be entirely disabled.
501 (Account Already Exists)
An account with that email address already exists in Bugzilla.
502 (Password Too Short)
The password specified is too short. (Usually, this means the password is under three characters.)
503 (Password Too Long)
The password specified is too long. (Usually, this means the password is over ten characters.
504 (Invalid User)
Either the QA Contact, Assignee, or CC lists have some invalid user in them. The error message will have more details.
505 (User Access By Id or User-Matching Denied)
Logged-out users cannot use the "ids" or "match" arguments to this function.