The Ceylon plugin doesn't work with Idea 2017.3

[akornilov]

After open any Ceylon project the message appears in the Event Log:
"Ceylon model update failed
The Ceylon model update triggered an unexpected exception: ceylon.language.AssertionError "Assertion failed: The PSI element should still exist
violated exists el = psiPointer.element" that will be reported in the Event View.
To avoid performance issues the automatic update of the Ceylon model has been disabled.
You can reenable it by using the following menu entry: Tools -> Ceylon -> Enable automatic update of model."

After that doesn't work:

• completer tool
• navigation in code
• build doesn't take into account any changes: program still can be build and run but any new changes in code not visible.

The hint from message "You can reenable it by using the following menu entry: Tools -> Ceylon -> Enable automatic update of model." is not working.

[akornilov]

From time to time this issue is also observed on 2017.2.5 (platform Windows 7 x64 Professional).

[lukedegruchy]

I'm experiencing the same thing. Only after downgrading to 2017.2 can I get the Ceylon plugin to work.

[luolong]

I can confirm this. Downgrading is not an option though.

[drhagen]

I recently upgraded from 2017.2 to 2018.1 and see this same error.