ABAP eclipse 打开ddl sources异常错误

 The editor can not be shown because the content can not be synchronized with the backend: Synchronize Content Result for /DR1_200_zhumin_zh/.adt/ddic/ddlsources/zcdsv_material_valueation/zcdsv_material_valueation.apddls; Request could not be understood by the server due to malformed syntax: Accept header missing.

从新安装 一下

参考地址 https://tools.hana.ondemand.com/#abap

Component	Prerequisite
Eclipse Platform	Mars (4.5)
Operating System	Windows 7/8, or Apple Mac OS X 10.8, Universal 64-Bit, or Linux distribution
Java Runtime	JRE version 1.6 or higher, 32-Bit or 64-Bit
SAP GUI	For Windows OS: SAP GUI for Windows 7.40 For Apple Mac or Linux OS: SAP GUI for Java 7.40
Microsoft VC Runtime	For Windows OS: DLLs VS2010 for communication with the back-end system is required. NOTE: Install either the x86 or the x64 variant, accordingly to your 32- or 64-Bit Eclipse installation.

Procedure

To install the front-end component of ADT, proceed as follows:

1. Get an installation of Eclipse Mars (e.g. Eclipse IDE for Java Developers)
2. In Eclipse, choose in the menu bar Help > Install New Software...
3. For Eclipse Mars (4.5), add the URL https://tools.hana.ondemand.com/mars  （mars改成eclipse的版本如 kepler）
   
4. Press Enter to display the available features.
5. Select ABAP Development Tools for SAP NetWeaver and choose Next.
6. On the next wizard page, you get an overview of the features to be installed. Choose Next.
7. Confirm the license agreements and choose Finish to start the installation.

以上为收集到的资料，

最终发现卸掉  ABAP Core Development Tools (Developer Edition)    组件，重新安装即可