Description of problem:
Related to bug 1019268.
It is allowed to put a plus sign in the file name when creating a new process (the Create new dialog), but the Designer cannot handle it. It shows 'Process loading errors' dialog instead of the process, with message:
"""
Could not open requested business process due to processing errors.
Empty process was loaded instead.
Click on the Details tab below to view error details.
"""
After closing this dialog, no empty process is opened - the Designer fails to finish loading.

Server log states that:
ERROR [org.drools.core.xml.ExtensibleXmlParser] (null: 4, 120): cvc-datatype-valid.1.2.1: 'project1.asd+asd' is not a valid value for 'NCName'.
ERROR [org.drools.core.xml.ExtensibleXmlParser] (null: 4, 120): cvc-attribute.3: The value 'project1.asd+asd' of attribute 'id' on element 'bpmn2:process' is not valid with respect to its type, 'ID'.
ERROR [org.drools.core.xml.ExtensibleXmlParser] (null: 8, 56): cvc-datatype-valid.1.2.1: 'project1.asd+asd' is not a valid value for 'QName'.
ERROR [org.drools.core.xml.ExtensibleXmlParser] (null: 8, 56): cvc-attribute.3: The value 'project1.asd+asd' of attribute 'bpmnElement' on element 'bpmndi:BPMNPlane' is not valid with respect to its type, 'QName'.

ERROR [org.jbpm.designer.web.preprocessing.impl.JbpmPreprocessingUnit] Failed to setup workitems : null
ERROR [stderr] org.uberfire.java.nio.file.NoSuchFileException
ERROR [stderr] at org.uberfire.java.nio.fs.jgit.JGitFileSystemProvider.readAttributes(JGitFileSystemProvider.java:1508)
...

Reopening the process has the same effect.

Version-Release number of selected component (if applicable):
BPMS 6.0 CR2