In the new Microsoft Dynamics 365 Finance and Operations release a lot of things have changed in terms of reflection. One of them that we have used frequently for security access validation is gone, DictSecurityKey is deprecated.
You can find a list of still available classes which are mostly used against AOT objects here:
For example when you wanted to hide a tab on a form in X++, you could just use reflection to do the validation like this:
dictSecurityKey = new DictSecurityKey(buildTabpage.securityKey()); (dictSecurityKey && dictSecurityKey.rights() != AccessType::Delete));
The security framework has been improved/redesigned in D365FO, and now you can achieve the same with the following code:
SecurityRights securityRights = SecurityRights::construct(); securityRights.formControlAccessRight(form.name(classId2Name(classIdGet(this))), buildTabpage.name()) != AccessRight::Delete;