无法为拆分生成资源表”

我正在尝试创建一个Android应用程序。目前它无法运行，并且会给我2个错误。

我不确定如何使第一个错误以及第二个错误消失。当我检查控制台时，这就是我得到的。

[2015-01-29 16:16:48 - TipCalculator] Failed to generate resource table for split ''
[2015-01-29 16:16:48 - TipCalculator] /Users/lewismenelaws/Documents/workspace/TipCalculator/res/values/dimens.xml:7: error: Error: String types not allowed (at 'textview_margin8dp' with value 'textview_margin 8dp').
[2015-01-29 16:16:48 - TipCalculator] 
[2015-01-29 16:17:04 - TipCalculator] Failed to generate resource table for split ''
[2015-01-29 16:17:04 - TipCalculator] /Users/lewismenelaws/Documents/workspace/TipCalculator/res/values/dimens.xml:7: error: Error: String types not allowed (at 'textview_margin8dp' with value 'textview_margin 8dp').
[2015-01-29 16:17:04 - TipCalculator] 
[2015-01-29 16:18:05 - TipCalculator] Failed to generate resource table for split ''
[2015-01-29 16:18:05 - TipCalculator] /Users/lewismenelaws/Documents/workspace/TipCalculator/res/values/dimens.xml:7: error: Error: String types not allowed (at 'textview_margin8dp' with value 'textview_margin 8dp').
[2015-01-29 16:18:05 - TipCalculator] 
[2015-01-29 16:26:28 - TipCalculator] Failed to generate resource table for split ''
[2015-01-29 16:26:28 - TipCalculator] /Users/lewismenelaws/Documents/workspace/TipCalculator/res/values/dimens.xml:7: error: Error: String types not allowed (at 'textview_margin8dp' with value 'textview_margin 8dp').
[2015-01-29 16:26:28 - TipCalculator] 
[2015-01-29 16:26:46 - TipCalculator] Failed to generate resource table for split ''
[2015-01-29 16:26:46 - TipCalculator] /Users/lewismenelaws/Documents/workspace/TipCalculator/res/values/dimens.xml:7: error: Error: String types not allowed (at 'textview_margin8dp' with value 'textview_margin 8dp').
[2015-01-29 16:26:46 - TipCalculator] 
[2015-01-29 16:27:49 - TipCalculator] Failed to generate resource table for split ''
[2015-01-29 16:27:49 - TipCalculator] /Users/lewismenelaws/Documents/workspace/TipCalculator/res/values/dimens.xml:7: error: Error: String types not allowed (at 'textview_margin8dp' with value 'textview_margin 8dp').
[2015-01-29 16:27:49 - TipCalculator] 
[2015-01-29 16:28:11 - TipCalculator] Failed to generate resource table for split ''
[2015-01-29 16:28:11 - TipCalculator] /Users/lewismenelaws/Documents/workspace/TipCalculator/res/values/dimens.xml:7: error: Error: String types not allowed (at 'textview_margin8dp' with value 'textview_margin 8dp').
[2015-01-29 16:28:11 - TipCalculator] 
[2015-01-29 16:29:32 - TipCalculator] Failed to generate resource table for split ''
[2015-01-29 16:29:32 - TipCalculator] /Users/lewismenelaws/Documents/workspace/TipCalculator/res/values/dimens.xml:7: error: Error: String types not allowed (at 'textview_margin8dp' with value 'textview_margin 8dp').
[2015-01-29 16:29:32 - TipCalculator] 
[2015-01-29 16:29:51 - TipCalculator] Failed to generate resource table for split ''
[2015-01-29 16:29:51 - TipCalculator] /Users/lewismenelaws/Documents/workspace/TipCalculator/res/values/dimens.xml:7: error: Error: String types not allowed (at 'textview_margin8dp' with value 'textview_margin 8dp').
[2015-01-29 16:29:51 - TipCalculator] 
[2015-01-29 16:29:51 - TipCalculator] Dx 
trouble writing output: already prepared

我不确定这意味着什么，也无法找到有效的解决方案。我试图清理/重建，但仍然没有帮助。谢谢你。

这是dimens.xml文件：

<resources>

    <!-- Default screen margins, per the Android Design guidelines. -->
    <dimen name="activity_horizontal_margin">16dp</dimen>
    <dimen name="activity_vertical_margin">16dp</dimen>
    <dimen name="textview_padding">8dp</dimen>
    <dimen name="textview_margin8dp">textview_margin 8dp</dimen>
    <dimen name="textview_margin">8db</dimen>

</resources>