This video walks through the new features in 5.0 https://youtu.be/VDp1w6xsGFo
PIAB 5.0 uses the .NET Framework 4.5.1, which includes new security features especially in the Browser App. There is built-in checking in IIS for cross-site scripting which attempts to protect against injection of malicious html markup and scripting codes entered into web forms. In some cases users may legitimately want to include html in certain text fields, and we have included exceptions for some of these. However, it is possible (but not recommended) to revert to not checking, using values in the web.config file.
See KB0000420 Web.Config File for more details.