Unable to Build & Upload Model in Designer 7.1.2

One of my colleagues is getting the following error upon Build & Upload for a new ProcessModel:


Build of process "BeP_OtC_BIS_deliverCustomerOrder_inBIS" started at Thu Jan 03 15:06:20 CET 2013 
Checking database for prior build and upload of process: "BeP_OtC_BIS_deliverCustomerOrder_inBIS" version: "1"
Retrieving previous build information for process: "BeP_OtC_BIS_deliverCustomerOrder_inBIS" version: "1"
Error: Failed to retrieve previous build information for process "{0}" version: "{1}". Please make sure that the database is configured properly.
null
at java.io.ByteArrayInputStream.<init>(Unknown Source)
at com.webmethods.process.generator.process.receipt.util.ProcessGenerationReceiptManager.parseBytes(ProcessGenerationReceiptManager.java:152)
at com.webmethods.process.generator.process.receipt.util.ProcessGenerationReceiptManager.getPreviousGenerationReceipt(ProcessGenerationReceiptManager.java:131)
at com.webmethods.process.generator.process.receipt.util.ProcessGenerationReceiptManager.getPreviousGenerationReceipt(ProcessGenerationReceiptManager.java:117)
at com.webmethods.process.generator.ProcessModelGenerator.readGeneratedComponentsFromGenerationReceipt(ProcessModelGenerator.java:424)
at com.webmethods.process.generator.ProcessModelGenerator.generateModel(ProcessModelGenerator.java:255)
at com.webmethods.process.generator.ProcessModelGenerator.generateModel(ProcessModelGenerator.java:463)
at com.webmethods.process.generator.actions.GenerateProcessAction.run(GenerateProcessAction.java:269)
... 30 more
Error: Build of process "BeP_OtC_BIS_deliverCustomerOrder_inBIS" failed. Please check the log file for more information.
java.lang.NullPointerException
at com.webmethods.process.generator.ProcessModelGenerator.setOldLogicalToPhysicalMapList(ProcessModelGenerator.java:1265)

I have checked the LogicalServer settings, the JDBC-Pool Settings and the Designer settings several times. All of them are correct and working.
Except for the Build & Upload.
I have checked also the Proxy Settings of the Designer but even this did not help.

Any Ideas?

Updating the DataDirect-Drivers in Designer as described in Knowledgebase-Article 1736911 helped.

Additional information:
Designer should be started as “eclipse.exe -clean” in a Command Prompt Window.

This cleans the plugin cache.