Action stopped working due to the recent upgrade in PhotoSHop CC 2018

As I wrote a little  Photoshop script to select a tool in an action before an action select a tools preset can get around that problem.  You would create a Photoshop script like ActivatePathSelectionTool.jsx and use a action step to select to that tool before the select tool preset preset name you would record a step menu File>Scripts>ActivatePathSelectionTool.  Actions can use scripts and some scripts are short and simple however much knowledge is required to write them.  Switching tool is simple but you need the knowledge.   I'll make that simple for you.  The odd thing is that is action manager code that the action recorder does not record for all tools.

selectTool('pathComponentSelectTool');
// =================================================== Helper functions ===================================================== //
function selectTool(tool) {
    var desc9 = new ActionDescriptor();
        var ref7 = new ActionReference();
        ref7.putClass( app.stringIDToTypeID(tool) );
    desc9.putReference( app.charIDToTypeID('null'), ref7 );
    executeAction( app.charIDToTypeID('slct'), desc9, DialogModes.NO );
};
/* Most of Photoshop tool internal names
'moveTool'                     'cloneStampTool'            'typeCreateOrEditTool'            'artboardTool'
'marqueeRectTool'              'patternStampTool'          'typeVerticalCreateOrEditTool'    'perspectiveCropTool'
'marqueeEllipTool'             'historyBrushTool'          'typeCreateMaskTool'              'eyedropperTool'              
'marqueeSingleRowTool'         'artBrushTool'              'typeVerticalCreateMaskTool'      '3DMaterialSelectTool'
'marqueeSingleColumnTool'      'eraserTool'                'pathComponentSelectTool'
'lassoTool'                    'backgroundEraserTool'      'directSelectTool'
'polySelTool'                  'magicEraserTool'           'rectangleTool'
'magneticLassoTool'            'gradientTool'              'roundedRectangleTool'
'quickSelectTool'              'bucketTool'                'ellipseTool'
'magicWandTool'                'blurTool'                  'polygonTool'
'cropTool'                     'sharpenTool'               'lineTool'
'sliceTool'                    'smudgeTool'                'customShapeTool'
'sliceSelectTool'              'dodgeTool'                 'textAnnotTool'
'spotHealingBrushTool'         'burnInTool'                'soundAnnotTool'
'magicStampTool'               'saturationTool'            'eyedropperTool'
'patchSelection'               'penTool'                   'colorSamplerTool'
'redEyeTool'                   'freeformPenTool'           'rulerTool'
'paintbrushTool'               'addKnotTool'               'handTool'
'pencilTool'                   'deleteKnotTool'            'zoomTool'
'colorReplacementBrushTool'    'convertKnotTool'           'wetBrushTool' 
*/

They most likely work the same way. It just that in the older version your UI setting is to show all tool presets which is not Adobe default setting.   Select "TOOL" preset is normally only able to select the current active tools presets not all of load presets for any tools.   Actions have dependencies.  With a little Photoshop script step in your action you can remove the dependency on presets  "Current tool only"  being unchecked.

Thanks Stephen this is a good work around. I have tested and it seems to correct the issue.

Then it is an Adobe Mac Photoshop Mac you should report it to Adobe. Adobe may fix the bug.  Adobe does not fix all reported and acknowledge bugs though.  It good that you have a work around for your Mac. Make Path from selection should make the Path created the Active Work Path...

I think you should still be able to do the.  There is a preference the may has some effect on this. I do not think it should. I do not install AI the Photoshop Preference is Export Clipboard.  I set mine not to.  I also created an action the creates two docyment in the first document it draws some black pixels.  Select the black pixels. Coverts the selection to a path. Copy the path.  Create the second document and paste in the path. here is a link http://www.mouseprints.net/old/dpr/Test.atn  see if after running the action in Photoshop past works in AI.

Without seeing your action and which step you have a problem with there is not much anyone can add. We have know idea of what kind of copy step you are using. You now seem to be stating it a copy to clipboard. That paste to Illustrator does not work.  Many here like myself do not install Illustrator.  So I could not even test if its the copy or Paste step that is failing.  I believe what you are trying to do is make the Path you created in the document the current active path.  Which I believe it should be after you convert the selection to a Path.  Copy should then copt the Pathe to the clicboard not the layers content of the layer. You mat have to doe a Deselect it the Active selection is still active After convert to Path.

When your action converts the active selection the Path that now pathe should be the current work path and ther should be no active selection. Copy should copy the work path to the clipboard.