The R55.13 update deletes required DLLs causing erratic re-install behavior throughout Quicken. A series of EO.xxxx.dll files are missing that affect Tax Planner. There is at least one more missing that affects QFX imports.
This issue has been reported numerous times in a forum which cannot be mentioned. It was left unresolved and has now infected the latest release.
Sanitized data files will not help troubleshoot. Install logs might. PD needs to determine why some Windows setups do not allow the dlls to install. It has been speculated it is because they are not digitally signed and Windows views them as a security risk.