Downloading VISIO: This error (HTTP 403 Forbidden) means that Internet Explorer was able to connect to the website, but it does not have permission to view the webpage.____

You have used the attribute named above in your document, but the document type you are using does not support that attribute for this element. This error is often caused by incorrect use of the "Strict" document type with a document that uses frames (e.g. you must use the "Transitional" document type to get the "target" attribute), or by using vendor proprietary extensions such as "marginheight" (this is usually fixed by using CSS to achieve the desired effect instead).

This error may also result if the element itself is not supported in the document type you are using, as an undefined element will have no supported attributes; in this case, see the element-undefined error message for further information.

How to fix: check the spelling and case of the element and attribute, (Remember XHTML is all lower-case) and/or check that they are both allowed in the chosen document type, and/or use CSS instead of this attribute. If you received this error when using the <embed> element to incorporate flash media in a Web page, see the FAQ item on valid flash.

An entity reference was found in the document, but there is no reference by that name defined. Often this is caused by misspelling the reference name, unencoded ampersands, or by leaving off the trailing semicolon (;).The most common cause of this error is unencoded ampersands in URLs as described by theWDG in "Ampersands in URLs".

Entity references start with an ampersand (&) and end with a semicolon (;). If you want to use a literal ampersand in your document you must encode it as "&amp;" (even inside URLs!). Be careful to end entity references with a semicolon or your entity reference may get interpreted in connection with the following text. Also keep in mind that named entity references are case-sensitive; &Aelig; and &aelig; are different characters.

If this error appears in some markup generated by PHP's session handling code,this article has explanations and solutions to your problem.

Note that in most documents, errors related to entity references will trigger up to 5 separate messages from the Validator. Usually these will all disappear when the original problem is fixed.

This is usually a cascading error caused by a an undefined entity reference or use of an unencoded ampersand (&) in an URL or body text. See the previous message for further details.

If you meant to include an entity that starts with "&", then you should terminate it with ";". Another reason for this error message is that you inadvertently created an entity by failing to escape an "&" character just before this text.

This is generally the sign of an ampersand that was not properly escaped for inclusion in an attribute, in a href for example. You will need to escape all instances of '&' into '&amp;'.

This is usually a cascading error caused by a an undefined entity reference or use of an unencoded ampersand (&) in an URL or body text. See the previous message for further details.

An entity reference was found in the document, but there is no reference by that name defined. Often this is caused by misspelling the reference name, unencoded ampersands, or by leaving off the trailing semicolon (;).The most common cause of this error is unencoded ampersands in URLs as described by theWDG in "Ampersands in URLs".

Entity references start with an ampersand (&) and end with a semicolon (;). If you want to use a literal ampersand in your document you must encode it as "&amp;" (even inside URLs!). Be careful to end entity references with a semicolon or your entity reference may get interpreted in connection with the following text. Also keep in mind that named entity references are case-sensitive; &Aelig; and &aelig; are different characters.

If this error appears in some markup generated by PHP's session handling code,this article has explanations and solutions to your problem.

Note that in most documents, errors related to entity references will trigger up to 5 separate messages from the Validator. Usually these will all disappear when the original problem is fixed.

This is usually a cascading error caused by a an undefined entity reference or use of an unencoded ampersand (&) in an URL or body text. See the previous message for further details.

If you meant to include an entity that starts with "&", then you should terminate it with ";". Another reason for this error message is that you inadvertently created an entity by failing to escape an "&" character just before this text.