Library Browser Plug-in Errors Remove the .dll files in PrgramData > Autodesk > Revit > Addins > 2019 > Pheinex > PEC Shared. Remove the Z .dll files in ProgramData > Autodesk > Revit > Addins > 2019 Run both programs. It may ask to uninstall so select uninstall. Install again. \\ictsccm1\sources$\Greg_Shunk_InstallsPECRevitMechanicalInstaller_v_1_4.msiRevitPECInstaller_v1_13.msi Double check above paths to make sure .dll files were installed.