After upgrade to 14.5 SP1 if REST query triggered by Policy Xpress is not finished under 30 seconds you see error in the server.log:
Read timed out
Identity Manager - Virtual Appliance 14.5. SP1
Please reach out to support to obtain hotfix. After installing it you will be able to set Rest Timeout.
To increase REST timeout, please add property "RestTimeout" to Miscellaneous section of Management console with value of timeout in seconds.
For example "50" without the quotes. This will ensure 50 second timeout is used.