Support » Plugin: Tailor Page Builder » JS error with canvas.min.js

  • Resolved bemdesign


    Running into what appears to be a JS issue with the canvas.min.js file:

    *Windows Server with IIS 7.5 running as User Acceptance Testing (staging environment)
    *This server running behind reverse proxy server
    *Custom Theme (based on _s, nothing much different beyond enqueing custom stylesheets and adding custom widget and menu areas)
    *Tailor 1.7.0

    Clicking Tailor This Page -> brings up the loading icon and two JavaScript error messages in the console.
    Uncaught TypeError: Cannot read property ‘findWhere’ of undefined
    Uncaught TypeError: Cannot read property ‘channel’ of undefined

    Unfortunately I can’t replicate this error in a local development environment (everything works fine there – the major difference being that local development doesn’t have to deal with a proxy server).

    Any ideas on what might be happening here?

    It appears that if you remove revisions or optimize the database, it will cause this issue. I can recreate the issue in local development after removing revisions (using Optimize Database after Deleting Revisions plugin). So the issue appears to revolve around revisions in the database.

    • This topic was modified 1 year, 10 months ago by  bemdesign. Reason: update from testing
Viewing 11 replies - 1 through 11 (of 11 total)
  • So further testing on a completely new draft page inside the UAT environment also brings up this JS error. Reverting back to 1.6.7 version of the plugin fixes the issue on local development. However it does not fix it on UAT. So there may be a server environment variable to the issue.

    • This reply was modified 1 year, 10 months ago by  bemdesign.
    • This reply was modified 1 year, 10 months ago by  bemdesign.

    Scratch that. Looks like reverting back to 1.6.7 of Tailor does fix the issue in the UAT environment. So apparently 1.7.0 introduced something that isn’t working in sites after doing a database clean/optimization (I tested the 1.7.0 version before the database clean/optimization so I know the 1.7.0 plugin works under standard conditions).

    So the question is, why would cleaning out post revisions and optimizing the database cause Tailor 1.7.0 to fail to work correctly and create javascript errors?

    I am also getting JS error Screenshot

    Plugin Author Andrew Worsfold


    Hi @bemdesign, @cantothemes,

    Thanks for bringing this to my attention. The problem actually was with the sidebar.min.js file; it somehow got corrupted and was causing the rest of the app to fail. The reason you were seeing it in some environments and not others is that the minified version is only used when SCRIPT_DEBUG is set to false.

    I’ve released a new version which includes the correct minified version. Can you please let me know if that works?


    Hello @andrewworsfold,

    Still one error is there I can’t edit my page.

    Plugin Author Andrew Worsfold


    What are you editing to receive that error? I am unable to reproduce that..

    1.7.1 looks to have fixed the issue in both environments I’ve tested in. Thanks again for such a quick response and fix!

    @cantothemes – I’m going to mark this thread resolved. If your issue still continues, open up a new support topic. Best of luck!


    I’m still seeing this error. We have downloaded the latest version. Is this something I can fix on my end?


    Plugin Author Andrew Worsfold


    Hi Todd,

    Are you seeing the exact error message above?

    The problem was caused by a corruption in the sidebar app and was something I could reproduce. I am seeing no such issue in the latest version, which makes me think that what you’re seeing is unrelated (canvas.min.js is essentially the entire preview pane app, so an error in that file doesn’t help diagnose the issue).

    Could you please let me know exactly what issue you’re seeing? Please also try using Tailor with a default theme and all other plugins disabled to see if that works.



    I’m getting the following errors. It appears to be related to our host (WP Engine). I’m only receiving the error on our hosted sites.

    Uncaught TypeError: Cannot read property ‘findWhere’ of undefined(…)
    Uncaught TypeError: Cannot read property ‘channel’ of undefined(…)

    This is with no other plugins and any theme.


    WP-Engine has tracked the issue to an interference with their mu-plugin. They are looking at where the issue. Did you have any incite as to where it might be?

    • This reply was modified 1 year, 9 months ago by  toddmckee. Reason: Update
Viewing 11 replies - 1 through 11 (of 11 total)
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