Hi, I have a file I've been working on for nearly a week in which suddenly 90% of my dimensions have gone to "error dimension" color (brown). I have no idea why this happened or what is wrong. When this happened I was adding dimensions to a block (not editing the block, just adding driven dims), one of the dims I was adding went to brown after I added a hole diameter with 'smart dimension'. I removed all of the dims I added but the brown nearly everywhere else remains. I had saved the file before I realized there was a problem so I don't have a copy of it from before the problem. I'm lost... the biggest frustration with this software is how it seemingly changes things unrelated to what is being added/edited, etc. If it happens outside of your current view it doesn't get noticed until later, if at all. Tim ETA: I went on and added more lines and dimensions to the drawing... and the error color has gone away for no apparent reason. This is very unsettling - if I lose a weeks worth of work on this... wow.
I'll try to explain the error(brown) dimension color as simply as I can. I will also offer some suggestions to help you with your design.
Error dimensions are a result of an error in associative solving.
Think of a dimension as a constraint just like connect, parallel horizontal/vertical, etc.
Constraints( and dimensions) help you define systems. A system is all the geometry and constraints that are related(dependently connected) in some way.
Think of a rectangle. This rectangle has 4 lines. These 4 lines are endpoint connected (4 constraints). These four lines have horizontal/vertical constraints (4 more constraints). There are 2 dimensons that define the length and height of the rectangle (2 more constraints). All of this defines the system that is the rectangle and allows you to control the size through modifying the dimensions.
All constraints, including dimensions, within a system are solved at the same time. That is the dimensions, endpoint connections, and horizontal/vertical constraints have equal importance to solve.
If a condition arises because of some modification where dimensions turn brown, that means that the system solve failed because of some reason. When you have hundereds of constraints and dimensions, it becomes dificult to pinpoint where the failure might occur and/or what caused it.
There are things you can do to help the situation of solve by making solve more simple. Look into Rigid Sets and Blocks.
If you are duplicating geometry use blocks. Within the block the geometry can be constrained and solves in the context of editing the block. But when the block is placed on your drawing, the other geometry on the drawing sees the block as a single object. This reduces the number of constraints solving on the sheet.
There are times when you are not duplicating geometry so blocks are not necessary, but the drawing is still getting complex. In this case you can start locking down parts of your drawing that you do not want to change. You can do this with Rigid Sets. A Rigid Set allows you to take a set of geometry and basically constrain all the geometry such that the geometry within the rigid set cannot change. The Rigid set is looked at by solve as a single entity like a block and can be moved around collectively. Solve will only react to constraints that are outside of the rigid set. You can later remove geometry from the rigid set if there is a need to make modifications to it.