This problem occurs in a project that works perfectly with ZOPE 2.6. After the upgrade to ZOPE 2.7.4 the user is asked for permission when ZClass code references a property defined in a property sheet. More detailed: A tal command of a ZPT inside a ZClass tries to access a property that is defined in a property sheet of the same ZClass, but is - of course - given a value in the instance of the class. In ZOPE 2.7.4 the user is asked to authenticate, and if he cancels authentication he gets the message: "Error > Value: You are not allowed to access 'teillisten_laenge' in this context". where teillisten_laenge is the property in question. This is just one example - the problem seems to occur in all similar cases. Here's the code fragment that tries to read the value of teillisten_laenge: <span tal:define="listen_laenge here/propertysheets/listenstil/teillisten_laenge"> <span tal:define="sort_kriterium string:id"> ... </span> </span> Someone confronted with the same problem? Seems to be a bug, or could it be wanted behaviour? Any proposals for a workaround? Thanks, Uli