Could you check the version of EPiServer.CMS.TinyMce package, make sure it is 2.x? Or can you see any js error?
We use the latest packages and I cannot see any js error.
I was told that this problem was there before updating to v 11
Which version of Forms and Epi.Cms are you using ?
Do you have any customization code ?
We need to have clue to find out the root cause.
As I said, I use the latest packages (EpiServerCMS.UI 11.12.1, TinyMce 2.7.0...) and the problem appeared before upgrading.
To give a little bit more context I use a customized SendEmailAfterSubmissionActor and I was able to use it on Alloy without any problem.
I compared side by side my solution and the Alloy demo. 2 js files are missing in my solution: FormContainer.js and EmailTemplateActorEditor.js.
PlaceHolderDropDownButton.js and PlaceHolderSelectorMenu.js are available in both solutions.
Does it help?
I have updated our solution with the latest EpiServer / forms packages and we are not able to see the 'Insert Placeholder' button.
I couldn't reproduce the problem with the Alloy demo site.
The difference is this service is called http://localhost:62906/EPiServer/EPiServer.Forms.UI/Stores/formsdata/ with the demo site (when I open the window) and not in our solution.
I cannot see any info in the log.
Any idea about how troubleshooting this issue?