According to error, subversion 1.8 or higher is required to commit to above repository, but subversion plugin is already on 2.5 and supports 1.8 SVN repository.

Below is the error trace:
Error

svn: E165001: Commit failed (details follow): svn: E165001: Commit blocked by start-commit hook (exit code 1) with output: Subversion 1.8 or greater is required to commit to this repository. svn: E175002: MKACTIVITY of '/svn/mainframe/!svn/act/e73af38c-4c01-0010-baae-91ffb01757b0': 500 Internal Server Error (https://peri.mojaair.com)

org.tmatesoft.svn.core.SVNException: svn: E165001: Commit failed (details follow):
svn: E165001: Commit blocked by start-commit hook (exit code 1) with output:
Subversion 1.8 or greater is required to commit to this repository.
svn: E175002: MKACTIVITY of '/svn/mainframe/!svn/act/e73af38c-4c01-0010-baae-91ffb01757b0': 500 Internal Server Error (https://peri.mojaair.com)
at org.tmatesoft.svn.core.internal.wc.SVNErrorManager.error(SVNErrorManager.java:64)
at org.tmatesoft.svn.core.internal.wc.SVNErrorManager.error(SVNErrorManager.java:51)
at org.tmatesoft.svn.core.internal.wc.SVNCopyDriver.copyReposToRepos(SVNCopyDriver.java:378)
at org.tmatesoft.svn.core.internal.wc.SVNCopyDriver.setupCopy(SVNCopyDriver.java:627)
at org.tmatesoft.svn.core.internal.wc16.SVNCopyClient16.doCopy(SVNCopyClient16.java:440)
at org.tmatesoft.svn.core.internal.wc2.remote.SvnNgReposToReposCopy.run(SvnNgReposToReposCopy.java:65)
at org.tmatesoft.svn.core.internal.wc2.remote.SvnNgReposToReposCopy.run(SvnNgReposToReposCopy.java:23)
at org.tmatesoft.svn.core.internal.wc2.SvnOperationRunner.run(SvnOperationRunner.java:21)
at org.tmatesoft.svn.core.wc2.SvnOperationFactory.run(SvnOperationFactory.java:1259)
at org.tmatesoft.svn.core.wc2.SvnOperation.run(SvnOperation.java:294)
at org.tmatesoft.svn.core.wc2.SvnRemoteCopy.run(SvnRemoteCopy.java:227)
at org.tmatesoft.svn.core.wc.SVNCopyClient.doCopy(SVNCopyClient.java:581)
at jenkins.plugins.svnmerge.IntegratableProjectAction.createSVNCopy(IntegratableProjectAction.java:260)
at jenkins.plugins.svnmerge.IntegratableProjectAction.doNewBranch(IntegratableProjectAction.java:208)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.kohsuke.stapler.Function$InstanceFunction.invoke(Function.java:298)
at org.kohsuke.stapler.interceptor.RequirePOST$Processor.invoke(RequirePOST.java:46)
at org.kohsuke.stapler.Function$InterceptedFunction.invoke(Function.java:399)
at org.kohsuke.stapler.Function.bindAndInvoke(Function.java:161)
at org.kohsuke.stapler.Function.bindAndInvokeAndServeResponse(Function.java:96)
at org.kohsuke.stapler.MetaClass$1.doDispatch(MetaClass.java:121)
at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:746)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:876)
at org.kohsuke.stapler.MetaClass$13.dispatch(MetaClass.java:411)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:746)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:876)
at org.kohsuke.stapler.MetaClass$6.doDispatch(MetaClass.java:249)
at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:746)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:876)
at org.kohsuke.stapler.Stapler.invoke(Stapler.java:649)
at org.kohsuke.stapler.Stapler.service(Stapler.java:238)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at hudson.util.PluginServletFilter$1.doFilter(PluginServletFilter.java:123)
at hudson.util.PluginServletFilter.doFilter(PluginServletFilter.java:114)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at hudson.security.csrf.CrumbFilter.doFilter(CrumbFilter.java:48)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:84)
at hudson.security.UnwrapSecurityExceptionFilter.doFilter(UnwrapSecurityExceptionFilter.java:51)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at jenkins.security.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:117)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at org.acegisecurity.providers.anonymous.AnonymousProcessingFilter.doFilter(AnonymousProcessingFilter.java:125)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at org.acegisecurity.ui.rememberme.RememberMeProcessingFilter.doFilter(RememberMeProcessingFilter.java:142)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at org.acegisecurity.ui.AbstractProcessingFilter.doFilter(AbstractProcessingFilter.java:271)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at jenkins.security.BasicHeaderProcessor.doFilter(BasicHeaderProcessor.java:93)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at org.acegisecurity.context.HttpSessionContextIntegrationFilter.doFilter(HttpSessionContextIntegrationFilter.java:249)
at hudson.security.HttpSessionContextIntegrationFilter2.doFilter(HttpSessionContextIntegrationFilter2.java:67)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:76)
at hudson.security.HudsonFilter.doFilter(HudsonFilter.java:168)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.kohsuke.stapler.compression.CompressionFilter.doFilter(CompressionFilter.java:49)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at hudson.util.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:81)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.kohsuke.stapler.DiagnosticThreadNameFilter.doFilter(DiagnosticThreadNameFilter.java:30)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:223)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:107)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:616)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:155)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:76)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:934)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:90)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:515)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1010)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:640)
at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:223)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1618)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1576)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:724)