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Global exceptions handling in IWS was improved to avoid having IWS close unexpectedly. All exceptions are now grouped by two types:
unhandled error
critical error
Unhandled error are automatically handled in code and you can click ignore these errors by clicking Ignore on the error dialog. While critical errors can't be ignored or fully handled within the code, you will now see a stack trace and be able to close IWS gracefully with a saving state.
This issue was tracked as Item #139271.
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