The problem of CAD not breaking down and exploding can be caused by a variety of reasons, including but not limited to the following:
1.The object is a block reference: If the object is a block reference, then it may not be able to be exploded or exploded. This is because a block reference is a monolithic object and cannot be broken down into individual entities.
2.The object is an external reference: If the object is an external reference, then it may not be able to be exploded or exploded. This is because xrefs are objects that are linked to other CAD files and cannot be edited or modified directly.
3.Objects are groups: If an object is a group, then it may not be able to be broken down or exploded. This is because a group is a whole made up of multiple entities that need to be ungrouped before they can be edited or modified.
4.The object is an external tile: If the object is an external tile, then it may not be able to be exploded or exploded. This is because external blocks are objects stored in other CAD files that need to be inserted into the current CAD file before they can be edited or modified.
In the above cases, you can take the following solutions:
1.If the object is a block reference, you can try using the explode command to break it down into separate entities.
2.If the object is an external reference, you can insert the external reference into the current CAD file before attempting to edit or modify it.
3.If the object is a group, you can use the group command to ungroup it before attempting to edit or modify it.
4.If the object is an external block, you can use the Insert command to insert it into the current CAD file before attempting to edit or modify it.
It is important to note that the above workaround may not be applicable in all cases. If none of the above methods can solve the problem, it is recommended to consult the help documentation of the relevant CAD software or seek professional help.