Bad char in solution- or language-name causes dubious erroneous behaviour

Hi,

After creating a solution with name "some?test" (caused by accidential keyboard-layout-switch -> should have been an "_") i get dubious failure-messages ("Project" is red underlined) and the solution is not shown within MPS but the entry

<solutionPath path="${project}/solutions/some?test/some?test.msd" />

exists within my .mpr-file. Afterwards i get follwoing failures from within MPS when building a language:

[jetbrains.mps.refactoring.framework.RefactoringContext] saving refactoring: refactoring jetbrains.mps.lang.structure.refactorings.RenameConcept is null
[jetbrains.mps.refactoring.framework.RefactoringContext] can't find a class jetbrains.mps.lang.structure.refactorings.RenameConcept in a language jetbrains.mps.lang.structure
[jetbrains.mps.refactoring.framework.RefactoringContext] refactoring for jetbrains.mps.lang.structure.refactorings.RenameConcept was not loaded

Even the removement of the above mentioned line does not lead to a normal behaviour of MPS :-(

See also http://youtrack.jetbrains.net/issue/MPS-6723

Mirko