Getting error migrating a project from Neoload 5.1 to Neoload 6.4

The Project(scripts) was created in Neoload 5.1
Now when we are trying to open the same project with Neoload 6.4, it is asking to migrate the project to Neoload 6.4. After clicking on Yes it is giving Migration error. Below are the error details:
com.neotys.nl.controller.config.migration.MigrationException: Cannot migrate D:\FromWebLoad\NeoloadNBUScripts\Foresters_Final.nlp: D:\FromWebLoad\NeoloadNBUScripts\config.zip
at com.neotys.nl.controller.config.migration.steps.AbstractMigrationStep.migrate(AbstractMigrationStep.java:93)
at com.neotys.nl.controller.config.migration.steps.DesignMigrationStep.apply(DesignMigrationStep.java:43)
at com.neotys.nl.controller.config.migration.steps.MigrationSteps.apply(MigrationSteps.java:38)
at com.neotys.nl.controller.config.ConfigurationManager.performOpenImpl(ConfigurationManager.java:991)
at com.neotys.nl.controller.config.ConfigurationManager.openProject(ConfigurationManager.java:834)
at com.neotys.nl.controller.config.ConfigurationManager.openProject(ConfigurationManager.java:801)
at com.neotys.nl.gui.b1.a(b1.java:1505)
at com.neotys.nl.gui.b1.a(b1.java:1422)
at com.neotys.nl.gui.a.q.run(q.java:33)
Caused by: com.neotys.nl.controller.data.NeoLoadConfigurationException: java.io.FileNotFoundException: D:\FromWebLoad\NeoloadNBUScripts\Foresters_Final.nlp (Access is denied)
at com.neotys.nl.controller.config.ConfigurationManager.saveProject(ConfigurationManager.java:2204)
at com.neotys.nl.controller.config.ConfigurationManager.saveProject(ConfigurationManager.java:1899)
at com.neotys.nl.controller.config.migration.MigrationConfiguration$1.saveProject(MigrationConfiguration.java:31)
at com.neotys.nl.controller.config.migration.steps.AbstractMigrationStep.migrate(AbstractMigrationStep.java:86)
... 8 more