Continuations with other open masters break the saving process

[01es]

Description

Saving of modified entities may require a continuation, which is represented by its own master. The simplest example is the Warning Acknowledgement continuation. However, if there was another Entity Master open from the master representing the entity being saved, displaying the continuation master fails due to that other Entity Master being open (only one master can be open at a time). This behaviour is consistent with the current design. However, what is not expected is that such failure is not recovered correctly -- the SAVE button remains disabled and the progress indicator keeps on spinning.

This situation needs to be improved by recovering the failure to show a continuation master and to allow users to save their changes.

Expected outcome

It is expected that such situation would be fully recoverable, allowing users to close extra masters and to continue with saving.