Try to do the following:
- Open the dot file which shall be located at %appdata%\Microsoft\Word\STARTUP
- Open the Visual Basic Editor (show macros, then click edit)
- Click on module 'ShellUtil' so the source code will be visible
- At the following location change keyword 'LongPtr' to 'Long', so it looks like the following
Private Declare Function WaitForSingleObject Lib "kernel32" ( _
ByVal hHandle As Long, _
ByVal dwMilliseconds As Long) As Long
- Save the macro (finally copy .dot to STARTUP-location if necessary) and restart Word.
This worked for me...
Stupid hint: when adding PlantUML to fresh Word file, keep cursor outside the "code" when pressing the 'Generate images'-button, otherwise you will get cryptic error