That AnkhSVN learns to recognize when files are deleted
Subject: Error handling PendingChangesCreatePatch (SVN_ERR_WC_PATH_UNEXPECTED_STATUS)
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Expected node '[...]\Content\jquery-ui\base\jquery.ui.accordion.css' to be added.
at SharpSvn.SvnClientArgs.HandleResult(SvnClientContext client, SvnException error, Object targets)
at SharpSvn.SvnClientArgs.HandleResult(SvnClientContext client, svn_error_t* error, Object targets)
at SharpSvn.SvnClient.Diff(SvnTarget source, SvnRevisionRange range, SvnDiffArgs args, Stream result)
at Ankh.Services.PendingChanges.PendingChangeHandler.<>c__DisplayClass4.<CreatePatch>b__0(Object sender, ProgressWorkerArgs e)
at Ankh.ProgressRunnerService.ProgressRunner.Run(Object arg)
It would be more helpful if you report this kind of problems with some reproduction recipe, to the standard error e-mail adress.
That way you would have found out that you have found a corner case issue in the Subversion core libraries instead of just annoying the developer(s) that you want to resolve your issue.
AnkhSVN internally just calls the backing implementation of 'svn diff' to provide you patch files, and if you tried long enough you would have been able to reproduce this issue yourself. (Which would have required copying some directories, deleting nodes in it, etc. which you didn't mention in your minimalistic report)
A good bug report would have been easy to bump/forward up to the Subversion project, as we can't resolve problems like this in just AnkhSVN or SharpSvn.
With all the missing information and after a few tests I'm guessing that the problem is already fixed since Subversion 1.8.5 which had some relevant fixes. Upgrading to the most recent AnkhSVN would then resolve your problem.