Diff view fails to compare files with Error: cannot show diff

Problem

When comparing files in the IDE, the diff view doesn't work and shows the error message "Error: cannot show diff." This issue occurs inconsistently and affects various file comparisons, including comparisons within a project or between Git branches or revisions. It is sporadic, happens on some files/projects, while it works on others.

Resolution

To resolve this issue, update the IDE to the latest stable release. For example, for IntelliJ: https://www.jetbrains.com/idea/download. For other IDEs, just replace idea with webstorm, pycharm etc.