A dangling dimension in a drawing occurs when changes to a model cause the dimension to lose it's reference. It will turn a yellowish-brown color. Sometimes you can click on the dimension to highlight it, click and drag on the red box at the end of the extension line, and re-attach it. If not, the dimension will need to be deleted and re-inserted.
I have three similar assembly views in the same drawing (SWx 2014 SP 0). Each of these assembly views has a cross-section view through the assembly center. Each assembly is a configuration within a single SLDASM file. The assembly is roughly tube shaped, so the assembly cross-section is roughly rectangular. I added a reference dim to each of the views to show the distance between two components / sub-assemblies. The dimensions show up as expected: SWx has no trouble solving the reference dimensions. After I edit parts in the assemblies (parts that are unrelated to the reference dimension parts) and activate the assembly view sheets, or sometimes after I close and re-open the drawing, one or more of the dimensions lose their attachment to the model. I correct this by dragging one of the dimensions attachment points to a model edge in the cross-section. Lo and behold, an hour or so later I'll switch to the assembly drawing sheet, or close and re-open the drawing, and one or more of the dimensions has lost its attachment to the model again.
Furthermore, detail views of the same problematic cross-sections also have dimensions to the some of the same model edges as the full cross-section dimensions, but these reference dimensions are to different edges within the assemblies. These dimensions also lose their attachment to the model. Ctrl-q doesn't fix the issue. I suppose I could convert the views to sketches & dimension those, but I want the assembly views to always be synced with the model if anything changes. Does anyone know what's happening and how to fix it?