If you find that your Notes Designer crashes when you try and open an NSF that has recently had conflicts resolved in source control it may be that a view has had the conflict resolution markup added.
This causes a DXL error and crashes designer. Remove the view from the On Disk Project and re-synchronise source control.
Notepad ++ has a useful tool for searching multiple text files.
Just a very quick tip.
If you are using the XPages simple action and you need to pass a parameter via the URL then you can do this. You will need to add it via the source as designer doesn’t support it via the properties.
<xp:parameter name="isRFM" value="Yes">
Gleaned from here – https://www.openntf.org/xspext/xpages%20extension%20library%20documentation.nsf/xpages-doc/xp_openPage.html