If you are running the Sun's JVM, set the following java properties in your mduml.properties* file: in the line JAVA_ARGS=-Xmx600M, change the number of heap size '600' to maximal heap size in megabytes.
For example:
JAVA_ARGS=-Xmx800M
This sets java heap size to 800 megabytes.
If you get exception "java.lang.OutOfMemoryError: PermGen space" please, check if PermSize is specified in mduml.properties* file.
The JAVA_ARGS line should look like:
JAVA_ARGS=-Xmx600M -XX\:PermSize\=40M -XX\:MaxPermSize\=150M
If PermSize is specified in mduml.properties* file and the same problem still appears, the MaxPermSize should be increased. PermSize is part of heap size, so MaxPermSize should always be smaller than heap size specified with Xmx parameter.
For example:
JAVA_ARGS=-Xmx600M -XX\:PermSize\=40M -XX\:MaxPermSize\=200M
* If you are using MagicDraw 17.0.5 or later, the name of the property file is magicdraw.properties.