I have a html extension developed and it is working on many computers nicely. Last week we have new macbook and i tried to install indesign, extension manager. Then i installed my selfsigned extension with the ExManCmd.
It shows that the extension is installed without any errors. unfortunately the extension panel is blank!!
As it is working on other computers there should not be problem with manifest or the paths i have given.
I tried to check paths and file permissions. everything looks fine.
What can be the reason for blank panel?
Have you tried to remote debug your extension? (catch error, exeptions, ...)?
You could also try to check logs files:
Hoping this will help.