A trusted source key is now required for the web applications.
This is described further in the 9.0
release notes:
35239 - The trusted source key, which can be used to specify that Where-clauses from the Web frontend are trusted, can now be specified as the ConnectionBehaviour/TrustedSourceKey option in the configuration file.
To correct this issue please follow the steps below:
To configure the trusted source key:
1. On the server where the web applications are installed, open a command line utility with administrator privileges.
2. Change to a directory with installed One Identity Manager development tools.
3. Run the following command:
imxclient edit-config /path <web.config file path> -T
(for example imxclient edit-config /path c:\inetpub\wwroot\apiserver\web.config -T)
or
imxclient edit-config /path <web.config file path> /trustedsourcekey <Key>