Enhanced Security will not turn off (Acrobat 9 / Ubuntu 16)

I am using Reader 9 on Ubuntu 16.6, working on a PDF from Youth in Action, which has a button to validate the organisation's registration number. Even though I have disabled Enhanced Security and added all possible websites from Youth in Action that it could be trying to access, the same error still appears:

"The Adobe Reader has the enhanced security feature enabled which prevens the PDF document from connecting to external services. To allow the connection choose the approprate option by click the options button in the yellow security warning bar. [NoAllowedError: Security setting sprevent access to this property or method.]"

Furthermore, I can not find a yellow security warning bar.