TypeError: Cannot read property 'effect' of null

Cocos Creator
#1

when I migrated my project from 2.3.3 to 2.3.4 I started getting the following error endlessly. when I then opened an old saved copy of the project in ver 2.3.3 the error still came.

TypeError: Cannot read property ‘effect’ of null
at addMeshToNode (/Applications/CocosCreator/Creator/2.3.4/CocosCreator.app/Contents/Resources/app.asar/editor/page/gizmos/utils/engine/2d.js:1:1591)
at Object.f.arrow (/Applications/CocosCreator/Creator/2.3.4/CocosCreator.app/Contents/Resources/app.asar/editor/page/gizmos/3d/elements/utils/controller-utils.js:1:573)
at module.exports.createAxis (/Applications/CocosCreator/Creator/2.3.4/CocosCreator.app/Contents/Resources/app.asar/editor/page/gizmos/3d/elements/controller/position-controller.js:1:657)
at module.exports.initShape (/Applications/CocosCreator/Creator/2.3.4/CocosCreator.app/Contents/Resources/app.asar/editor/page/gizmos/3d/elements/controller/position-controller.js:1:1268)
at new module.exports (/Applications/CocosCreator/Creator/2.3.4/CocosCreator.app/Contents/Resources/app.asar/editor/page/gizmos/3d/elements/controller/position-controller.js:1:619)
at module.exports.createController (/Applications/CocosCreator/Creator/2.3.4/CocosCreator.app/Contents/Resources/app.asar/editor/page/gizmos/3d/elements/transform/position-gizmo.js:1:552)
at module.exports.init (/Applications/CocosCreator/Creator/2.3.4/CocosCreator.app/Contents/Resources/app.asar/editor/page/gizmos/3d/elements/transform/position-gizmo.js:1:470)
at module.exports.init (/Applications/CocosCreator/Creator/2.3.4/CocosCreator.app/Contents/Resources/app.asar/editor/page/gizmos/2d/elements/transform/position-gizmo.js:1:372)
at module.exports.show (/Applications/CocosCreator/Creator/2.3.4/CocosCreator.app/Contents/Resources/app.asar/editor/page/gizmos/2d/elements/gizmo.js:1:4650)
at module.exports.update (/Applications/CocosCreator/Creator/2.3.4/CocosCreator.app/Contents/Resources/app.asar/editor/page/gizmos/2d/elements/gizmo.js:1:4263)

this error appears when I click on any ui element in the node tree. can someone please help?

thanks!

P.S. Does the above error have anything to do with the upgrade instructions:

Upgrade from < 2.3.3 version

  • The CCTexture2D and CCTexture2DRGB methods in the Effect have been abandoned.

I am using method CCTexture in some effects in my project.

#2

I was able to fix the problem by removing the effect files from the project. however I need to make custom effects for my project and now I don’t know where to keep them.
can someone help?

Thanks!