This is a 7u51 hardening feature. You cannot bypass it unless the app developer re-signs the JAR with the Permissions: all-permissions attribute. You may need to downgrade to JRE 7u25 if you absolutely cannot modify the app.
You will see multiple download files. Select the one matching your system: This is a 7u51 hardening feature
Why are people still searching for this exact version? This is a 7u51 hardening feature
It resolved several critical vulnerabilities (CVEs) found in earlier iterations of Java 7. How to Download Oracle Java SE JRE 7u51 This is a 7u51 hardening feature