Pega Personal Edition 8.3 is not starting up. It has been working fine for more than a year but stopped working suddenly. 

I am seeing below error in logs. Complete logs are attached as well. 

2021-03-16 06:52:16,164 [TIALIZE_DSM_SERVICES] [  STANDARD] [                    ] [                    ] (prpc.service.ServiceDefinition) ERROR   - Unable to create DSM service DATA-DECISION-SERVICE-ADM java.lang.ClassNotFoundException:      at java.lang.Class.forName0(Native Method) ~[?:1.8.0_121]     at java.lang.Class.forName(Class.java:264) ~[?:1.8.0_121]     at com.pega.dsm.dnode.impl.prpc.service.ServiceDefinition.instantiateService(ServiceDefinition.java:112) ~[d-node.jar:?]     at com.pega.dsm.dnode.impl.prpc.service.ServiceDefinition.<init>(ServiceDefinition.java:44) ~[d-node.jar:?]     at com.pega.dsm.dnode.impl.prpc.service.ServiceDefinition.<init>(ServiceDefinition.java:23) ~[d-node.jar:?]     at com.pega.dsm.dnode.impl.prpc.service.ServiceDefinition$Builder.build(ServiceDefinition.java:213) ~[d-node.jar:?]     at com.pega.dsm.dnode.impl.prpc.service.ServiceConfiguration$InstantiateServices.getServiceDefinitions(ServiceConfiguration.java:98) ~[d-node.jar:?]     at com.pega.dsm.dnode.impl.prpc.service.ServiceConfiguration$InstantiateServices.getRegisteredServicesFromDatabase(ServiceConfiguration.java:78) ~[d-node.jar:?]     at com.pega.dsm.dnode.impl.prpc.service.ServiceConfiguration$InstantiateServices.access$300(ServiceConfiguration.java:69) ~[d-node.jar:?]     at com.pega.dsm.dnode.impl.prpc.service.ServiceConfiguration$Builder.usePlatformRegisteredServices(ServiceConfiguration.java:60) ~[d-node.jar:?]     at com.pega.dsm.dnode.api.prpc.service.ServiceManager.bootstrap(ServiceManager.java:135) ~[d-node.jar:?]     at com.pega.dsm.dnode.api.prpc.service.DsmServicesInitializationTask$1.run(DsmServicesInitializationTask.java:29) ~[d-node.jar:?]     at com.pega.dsm.dnode.api.prpc.service.DsmServicesInitializationTask$1.run(DsmServicesInitializationTask.java:26) ~[d-node.jar:?]     at com.pega.dsm.dnode.util.PrpcRunnable.execute(PrpcRunnable.java:52) ~[d-node.jar:?]     at com.pega.dsm.dnode.impl.prpc.service.ServiceHelper.executeInPrpcContextInternal(ServiceHelper.java:259) ~[d-node.jar:?]     at com.pega.dsm.dnode.impl.prpc.service.ServiceHelper.executeInPrpcContext(ServiceHelper.java:108) ~[d-node.jar:?]     at com.pega.dsm.dnode.api.prpc.service.DsmServicesInitializationTask.runTask(DsmServicesInitializationTask.java:26) ~[d-node.jar:?]     at com.pega.pegarules.session.internal.async.startup.StartupTask$1.run(StartupTask.java:35) ~[prprivate-session.jar:?]     at com.pega.pegarules.session.internal.PRSessionProviderImpl.performTargetActionWithLock(PRSessionProviderImpl.java:1382) ~[prprivate-session.jar:?]     at com.pega.pegarules.session.internal.PRSessionProviderImpl.doWithRequestorLocked(PRSessionProviderImpl.java:1125) ~[prprivate-session.jar:?]     at com.pega.pegarules.session.internal.PRSessionProviderImpl.doWithRequestorLocked(PRSessionProviderImpl.java:932) ~[prprivate-session.jar:?]     at com.pega.pegarules.session.internal.PRSessionProviderImpl.doWithRequestorLocked(PRSessionProviderImpl.java:898) ~[prprivate-session.jar:?]     at com.pega.pegarules.session.internal.async.startup.StartupTask.run(StartupTask.java:30) ~[prprivate-session.jar:?]     at java.lang.Thread.run(Thread.java:745) [?:1.8.0_121] 2021-03-16 06:52:16,166 [TIALIZE_DSM_SERVICES] [  STANDARD] [                    ] [                    ] (   prpc.service.ServiceManager) ERROR   - Service manager failed to startup com.pega.pegarules.pub.PRRuntimeError: PRRuntimeError     at com.pega.dsm.dnode.impl.prpc.service.ServiceDefinition.instantiateService(ServiceDefinition.java:124) ~[d-node.jar:?]     at com.pega.dsm.dnode.impl.prpc.service.ServiceDefinition.<init>(ServiceDefinition.java:44) ~[d-node.jar:?]     at com.pega.dsm.dnode.impl.prpc.service.ServiceDefinition.<init>(ServiceDefinition.java:23) ~[d-node.jar:?]     at com.pega.dsm.dnode.impl.prpc.service.ServiceDefinition$Builder.build(ServiceDefinition.java:213) ~[d-node.jar:?]     at com.pega.dsm.dnode.impl.prpc.service.ServiceConfiguration$InstantiateServices.getServiceDefinitions(ServiceConfiguration.java:98) ~[d-node.jar:?]     at com.pega.dsm.dnode.impl.prpc.service.ServiceConfiguration$InstantiateServices.getRegisteredServicesFromDatabase(ServiceConfiguration.java:78) ~[d-node.jar:?]     at com.pega.dsm.dnode.impl.prpc.service.ServiceConfiguration$InstantiateServices.access$300(ServiceConfiguration.java:69) ~[d-node.jar:?]     at com.pega.dsm.dnode.impl.prpc.service.ServiceConfiguration$Builder.usePlatformRegisteredServices(ServiceConfiguration.java:60) ~[d-node.jar:?]     at com.pega.dsm.dnode.api.prpc.service.ServiceManager.bootstrap(ServiceManager.java:135) ~[d-node.jar:?]     at com.pega.dsm.dnode.api.prpc.service.DsmServicesInitializationTask$1.run(DsmServicesInitializationTask.java:29) ~[d-node.jar:?]     at com.pega.dsm.dnode.api.prpc.service.DsmServicesInitializationTask$1.run(DsmServicesInitializationTask.java:26) ~[d-node.jar:?]     at com.pega.dsm.dnode.util.PrpcRunnable.execute(PrpcRunnable.java:52) ~[d-node.jar:?]     at com.pega.dsm.dnode.impl.prpc.service.ServiceHelper.executeInPrpcContextInternal(ServiceHelper.java:259) ~[d-node.jar:?]     at com.pega.dsm.dnode.impl.prpc.service.ServiceHelper.executeInPrpcContext(ServiceHelper.java:108) ~[d-node.jar:?]     at com.pega.dsm.dnode.api.prpc.service.DsmServicesInitializationTask.runTask(DsmServicesInitializationTask.java:26) ~[d-node.jar:?]     at com.pega.pegarules.session.internal.async.startup.StartupTask$1.run(StartupTask.java:35) ~[prprivate-session.jar:?]     at com.pega.pegarules.session.internal.PRSessionProviderImpl.performTargetActionWithLock(PRSessionProviderImpl.java:1382) ~[prprivate-session.jar:?]     at com.pega.pegarules.session.internal.PRSessionProviderImpl.doWithRequestorLocked(PRSessionProviderImpl.java:1125) ~[prprivate-session.jar:?]     at com.pega.pegarules.session.internal.PRSessionProviderImpl.doWithRequestorLocked(PRSessionProviderImpl.java:932) ~[prprivate-session.jar:?]     at com.pega.pegarules.session.internal.PRSessionProviderImpl.doWithRequestorLocked(PRSessionProviderImpl.java:898) ~[prprivate-session.jar:?]     at com.pega.pegarules.session.internal.async.startup.StartupTask.run(StartupTask.java:30) ~[prprivate-session.jar:?]     at java.lang.Thread.run(Thread.java:745) [?:1.8.0_121] Caused by: java.lang.ClassNotFoundException:      at java.lang.Class.forName0(Native Method) ~[?:1.8.0_121]     at java.lang.Class.forName(Class.java:264) ~[?:1.8.0_121]     at com.pega.dsm.dnode.impl.prpc.service.ServiceDefinition.instantiateService(ServiceDefinition.java:112) ~[d-node.jar:?]     ... 21 more