ClassCastException: class org.eclipse.jdt.internal.core.JavaNature cannot be cast to class org.eclipse.jdt.core.lJavaProject

[losmurfs]

When I try Quick Fix I get:
No fixes available for 'java.lang.ClassCastException: class org.eclipse.jdt.internal.core.JavaNature
cannot be cast to class org.eclipse.jdt.core.lJavaProject (org.eclipse.jdt.internal.core.JavaNature and
org.eclipse.jdt.core.IJavaProject are in unnamed module of loader
org.eclipse.osgi.internal.loader.EquinoxClassLoader @7b657449)
class org.eclipse.jdt.internal.core.JavaNature cannot be cast to class org.eclipse.jdt.core.IJavaProject
(org.eclipse.jdt.internal.core.JavaNature and org.eclipse.jdt.core.lJavaProject are in unnamed
module of loader org.eclipse.osgi.internal.loader.EquinoxClassLoader @7b657449)'.

[nitind]

Which Quick Fix and on which release?

[nitind]

@losmurfs Also, when doing what Quick Fix?