When I try to submit an HTML link in a custom field of the type Memo/Rich Text Editor, in some cases I get the error message:
There is a validation error with your HTML input. Your activity is a bit suspicious, hence aborting
The input is a hyperlink in the most simple form:
<a href="https://www.example.com">Link text</a>
What's especially strange is that there are more fields of the same type in the same form that accept exactly the same HTML syntax.
I found no difference between using TinyMCE and CKEditor.
CiviCRM version is 4.4.19.
Any clues highly welcomed.