This is essentially an emergency release, to resolve an obtuse, but fatal problem caused, at least in part, by Diff itself. The situation involved large numbers of diffs having a low correlation of matching lines, such that Diff created regions consisting of a single line from one file against a range of lines from the other. Unfortunately if that first paired line was actually IDENTICAL, the inline-diffing options in TkDiff would fail to find ANY difference (a condition it was not expecting). As the issue was completely data-driven, fatal, and virtually impossible to anticipate, we felt a rapid response fix was warranted. We apologize for any installation churn issues you may experience as a result. Nonetheless, the issue has been resolved. We appreciate your continued interest in TkDiff.