Svn java api "Unable to open ra_local session for url"

I need to automatically check out all svn versions in order to do some repo mining.

I wrote Java code using svnkit (org.tmatesoft.svn_1.8.5.standalone_2) The code works well when I access the repository url but when I do checkout using the file: /// protocol the following svn exception appears.

I searched and found many recommendations such as version mismatch in client and server. but i don't have a client server. I only have Java code.

I checked out a review on my local drive and then I expect to use the repo on the local drive to automatically check for old versions offline.

I cannot figure out the solution and I am a beginner.

Do you have a solution?

An exception:

Exception in thread "main" org.tmatesoft.svn.core.SVNException: svn: E180001: Unable to open an ra_local session to URL
svn: E180001: Unable to open repository 'file: /// c: / repos / lego'
svn: E180001: Unable to open repository 'file: /// c: / repos / lego'
    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.io.fs.FSRepository.openRepository (FSRepository.java:796)
    at org.tmatesoft.svn.core.internal.io.fs.FSRepository.testConnection (FSRepository.java:105)
    at org.tmatesoft.svn.core.io.SVNRepository.getRepositoryRoot (SVNRepository.java:323)
    at org.tmatesoft.svn.core.internal.wc2.ng.SvnNgAbstractUpdate.checkout (SvnNgAbstractUpdate.java:768)
    at org.tmatesoft.svn.core.internal.wc2.ng.SvnNgCheckout.run (SvnNgCheckout.java:16)
    at org.tmatesoft.svn.core.internal.wc2.ng.SvnNgCheckout.run (SvnNgCheckout.java:10)
    at org.tmatesoft.svn.core.internal.wc2.ng.SvnNgOperationRunner.run (SvnNgOperationRunner.java:20)
    at org.tmatesoft.svn.core.internal.wc2.SvnOperationRunner.run (SvnOperationRunner.java:20)
    at org.tmatesoft.svn.core.wc2.SvnOperationFactory.run (SvnOperationFactory.java:1149)
    at org.tmatesoft.svn.core.wc2.SvnOperation.run (SvnOperation.java:294)
    at org.tmatesoft.svn.core.wc.SVNUpdateClient.doCheckout (SVNUpdateClient.java:777)
    at org.tmatesoft.svn.core.wc.SVNUpdateClient.doCheckout (SVNUpdateClient.java:662)
    at SVNHelper.doCheckou (SVNHelper.java:77)
    at process2.main (process2.java:20)