Since I've upgraded to InDesign 18.3 both the text wrap and gradient windows are blank when I select a text box or object. Any one experiencing the same? I don't know if there are other items that are affected, but these are the first I've come across.
Windows: Start InDesign, and then press Shift+Ctrl+Alt. Click Yes when asked if you want to delete preference files. macOS: While pressing Shift+Option+Command+Control, start InDesign. Click Yes when asked if you want to delete preference files. A dialog will appear asking to delete the InDesign Preferences, select 'Yes' on this dialog. Further info and instructions here if needed: https://helpx.adobe.com/in/indesign/kb/indesign-preferences-support-file-locations.html