we have an on-premise installation of confluence, which has been working perfectly well for the past 2 years. Today, when I tried to access our confluence page, I see the following error message, that complains about unexpectedRollbackException

I tried to restart the confluence server, but still get the same error. atlassian-confluence.log for startup is given below - any help will be appreciated!
2018-06-04 12:56:09,881 INFO [localhost-startStop-1] [com.atlassian.confluence.lifecycle] contextInitialized Starting Confluence 5.10.7 [build 6441 based on commit hash 08fdc84b52e6e9048619981d39d86d9bfcc50916]
2018-06-04 12:56:13,597 INFO [localhost-startStop-1] [springframework.web.context.ContextLoader] initWebApplicationContext Root WebApplicationContext: initialization started
2018-06-04 12:56:18,912 INFO [localhost-startStop-1] [com.atlassian.confluence.lifecycle] <init> Loading EhCache cache manager
2018-06-04 12:56:21,391 WARN [localhost-startStop-1] [org.springframework.beans.GenericTypeAwarePropertyDescriptor] getWriteMethodForActualAccess Invalid JavaBean property 'cacheFactory' being accessed! Ambiguous write methods found next to actually used [public void com.atlassian.confluence.spaces.persistence.dao.hibernate.HibernateSpaceDao.setCacheFactory(com.atlassian.vcache.VCacheFactory)]: [public void com.atlassian.confluence.core.persistence.hibernate.VersionedHibernateObjectDao.setCacheFactory(com.atlassian.cache.CacheFactory)]
2018-06-04 12:56:39,851 INFO [localhost-startStop-1] [springframework.web.context.ContextLoader] initWebApplicationContext Root WebApplicationContext: initialization completed in 26254 ms
2018-06-04 12:56:48,995 INFO [localhost-startStop-1] [atlassian.plugin.manager.DefaultPluginManager] earlyStartup Plugin system earlyStartup begun
2018-06-04 12:57:15,956 WARN [ThreadPoolAsyncTaskExecutor::Thread 7] [spring.scanner.util.ProductFilterUtil] detectProduct Couldn't detect product, will use ProductFilter.ALL
2018-06-04 12:57:16,488 WARN [ThreadPoolAsyncTaskExecutor::Thread 23] [spring.scanner.util.ProductFilterUtil] detectProduct Couldn't detect product, will use ProductFilter.ALL
2018-06-04 12:57:22,007 WARN [ThreadPoolAsyncTaskExecutor::Thread 1] [spring.scanner.util.ProductFilterUtil] detectProduct Couldn't detect product, will use ProductFilter.ALL
2018-06-04 12:57:22,023 WARN [ThreadPoolAsyncTaskExecutor::Thread 20] [spring.scanner.util.ProductFilterUtil] detectProduct Couldn't detect product, will use ProductFilter.ALL
2018-06-04 12:57:22,037 WARN [ThreadPoolAsyncTaskExecutor::Thread 3] [spring.scanner.util.ProductFilterUtil] detectProduct Couldn't detect product, will use ProductFilter.ALL
2018-06-04 12:57:22,319 WARN [ThreadPoolAsyncTaskExecutor::Thread 12] [spring.scanner.util.ProductFilterUtil] detectProduct Couldn't detect product, will use ProductFilter.ALL
2018-06-04 12:57:22,600 WARN [ThreadPoolAsyncTaskExecutor::Thread 20] [spring.scanner.util.ProductFilterUtil] detectProduct Couldn't detect product, will use ProductFilter.ALL
2018-06-04 12:57:50,601 INFO [localhost-startStop-1] [atlassian.plugin.manager.DefaultPluginManager] logTime Plugin system earlyStartup ended
2018-06-04 12:57:50,644 INFO [localhost-startStop-1] [atlassian.plugin.manager.DefaultPluginManager] lateStartup Plugin system lateStartup begun
2018-06-04 12:57:53,938 WARN [ThreadPoolAsyncTaskExecutor::Thread 1] [spring.scanner.util.ProductFilterUtil] detectProduct Couldn't detect product, will use ProductFilter.ALL
2018-06-04 12:57:57,611 WARN [AtlassianEvent::CustomizableThreadFactory-1] [core.persistence.schema.StartupSchemaChecker] handleWarnings Database schema is inconsistent with expectations. 3 potential issues found, see below for details.
2018-06-04 12:57:57,612 WARN [AtlassianEvent::CustomizableThreadFactory-1] [core.persistence.schema.StartupSchemaChecker] handleWarnings Column [lowerspacekey] of table [spaces] has mismatched definitions for expected [Column spaces.lowerspacekey nvarchar2(255) nullable] and actual [Column spaces.lowerspacekey nvarchar2(255) non-nullable]
2018-06-04 12:57:57,612 WARN [AtlassianEvent::CustomizableThreadFactory-1] [core.persistence.schema.StartupSchemaChecker] handleWarnings Column [lowerurl] of table [extrnlnks] has mismatched definitions for expected [Column extrnlnks.lowerurl nvarchar2(255) nullable] and actual [Column extrnlnks.lowerurl nvarchar2(255) non-nullable]
2018-06-04 12:57:57,612 WARN [AtlassianEvent::CustomizableThreadFactory-1] [core.persistence.schema.StartupSchemaChecker] handleWarnings Column [lowerurl] of table [trackbacklinks] has mismatched definitions for expected [Column trackbacklinks.lowerurl nvarchar2(255) nullable] and actual [Column trackbacklinks.lowerurl nvarchar2(255) non-nullable]
2018-06-04 12:58:07,424 INFO [localhost-startStop-1] [atlassian.plugin.manager.DefaultPluginManager] logTime Plugin system lateStartup ended
2018-06-04 12:58:13,742 INFO [localhost-startStop-1] [confluence.upgrade.impl.DefaultUpgradeGate] waitForBooleanValue Waiting to find if plugin dependent upgrades are required. Maximum wait time will be 90 seconds.
2018-06-04 12:58:13,743 INFO [localhost-startStop-1] [confluence.upgrade.impl.DefaultUpgradeGate] waitForBooleanValue plugin dependent upgrades are required : false.
2018-06-04 12:58:16,234 ERROR [localhost-startStop-1] [sf.hibernate.util.JDBCExceptionReporter] logExceptions ORA-01555: snapshot too old: rollback segment number with name "" too small
ORA-22924: snapshot too old
2018-06-04 12:58:16,235 ERROR [localhost-startStop-1] [sf.hibernate.util.JDBCExceptionReporter] logExceptions ORA-01555: snapshot too old: rollback segment number with name "" too small
ORA-22924: snapshot too old
2018-06-04 12:58:16,237 WARN [localhost-startStop-1] [confluence.impl.vcache.SynchronousExternalCache] lambda$get$11 Failed to read entry from cache 'com.atlassian.bandana.BandanaPersister': Failed due to UNCLASSIFIED_FAILURE
2018-06-04 12:58:16,273 WARN [localhost-startStop-1] [confluence.setup.bandana.ConfluenceDaoBandanaPersister] getObjectFromValue Configuration could not be loaded because class could not be found (context: null, key: null).
java.lang.NullPointerException: null
java.lang.NullPointerException
at java.io.StringReader.<init>(StringReader.java:50)
at com.atlassian.confluence.setup.bandana.ConfluenceDaoBandanaPersister.getObjectFromValue(ConfluenceDaoBandanaPersister.java:100)
at com.atlassian.confluence.setup.bandana.ConfluenceDaoBandanaPersister.retrieve(ConfluenceDaoBandanaPersister.java:30)
at sun.reflect.GeneratedMethodAccessor238.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:302)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:208)
at com.sun.proxy.$Proxy34.retrieve(Unknown Source)
at com.atlassian.confluence.setup.bandana.ConfluenceCachingBandanaPersister.lambda$retrieve$0(ConfluenceCachingBandanaPersister.java:80)
at com.atlassian.confluence.impl.vcache.SynchronousExternalCache.lambda$get$11(SynchronousExternalCache.java:239)
at com.atlassian.confluence.impl.concurrency.CompletionStageUtils.lambda$foldResult$0(CompletionStageUtils.java:19)
at java.util.concurrent.CompletableFuture.uniHandle(CompletableFuture.java:822)
at java.util.concurrent.CompletableFuture.uniHandleStage(CompletableFuture.java:834)
at java.util.concurrent.CompletableFuture.handle(CompletableFuture.java:2155)
at java.util.concurrent.CompletableFuture.handle(CompletableFuture.java:110)
at com.atlassian.confluence.impl.concurrency.CompletionStageUtils.foldResult(CompletionStageUtils.java:19)
at com.atlassian.confluence.impl.vcache.SynchronousExternalCache.get(SynchronousExternalCache.java:236)
at com.atlassian.confluence.setup.bandana.ConfluenceCachingBandanaPersister.retrieve(ConfluenceCachingBandanaPersister.java:78)
at com.atlassian.confluence.setup.bandana.ConfluenceCachingBandanaPersister.retrieve(ConfluenceCachingBandanaPersister.java:71)
at com.atlassian.bandana.DefaultBandanaManager.getValue(DefaultBandanaManager.java:32)
at com.atlassian.bandana.DefaultBandanaManager.getValue(DefaultBandanaManager.java:24)
at com.atlassian.confluence.schedule.persistence.dao.CachedScheduledJobDao.getScheduledJobHistory(CachedScheduledJobDao.java:124)
at com.atlassian.confluence.schedule.quartz.ManagedScheduledJobTriggerFactory.createAndRegisterTrigger(ManagedScheduledJobTriggerFactory.java:168)
at com.atlassian.confluence.schedule.quartz.ManagedScheduledJobTriggerFactory.initialiseTriggers(ManagedScheduledJobTriggerFactory.java:102)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:302)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:208)
at com.sun.proxy.$Proxy132.initialiseTriggers(Unknown Source)
at com.atlassian.confluence.schedule.listeners.ManagedScheduledJobsLifecycle.startup(ManagedScheduledJobsLifecycle.java:24)
at com.atlassian.config.lifecycle.DefaultLifecycleManager.startUp(DefaultLifecycleManager.java:40)
at com.atlassian.config.lifecycle.LifecycleServletContextListener.contextInitialized(LifecycleServletContextListener.java:17)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4842)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5303)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1407)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1397)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
2018-06-04 12:58:16,331 ERROR [localhost-startStop-1] [atlassian.config.lifecycle.LifecycleManager] panicAndShutdown Unable to start up Confluence. Fatal error during startup sequence: confluence.lifecycle.core:mananagedjobs (Start and stop the Managed Scheduled Jobs) - org.springframework.transaction.UnexpectedRollbackException: Transaction rolled back because it has been marked as rollback-only
org.springframework.transaction.UnexpectedRollbackException: Transaction rolled back because it has been marked as rollback-only
at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:724)
at sun.reflect.GeneratedMethodAccessor59.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:302)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
at com.sun.proxy.$Proxy32.commit(Unknown Source)
at org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:485)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:291)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:208)
at com.sun.proxy.$Proxy132.initialiseTriggers(Unknown Source)
at com.atlassian.confluence.schedule.listeners.ManagedScheduledJobsLifecycle.startup(ManagedScheduledJobsLifecycle.java:24)
at com.atlassian.config.lifecycle.DefaultLifecycleManager.startUp(DefaultLifecycleManager.java:40)
at com.atlassian.config.lifecycle.LifecycleServletContextListener.contextInitialized(LifecycleServletContextListener.java:17)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4842)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5303)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1407)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1397)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)