This issue came up last week and Trimble is trying to fix it at source, however we have a fix for this today as a work around. The issue is caused by Blocks that have a line type called Multiline in the blocks. If encountered the symptom is that you explode Blocks, and if you select Delete Blocks after exploding checked on, that the blocks disappear yet no linework at all is created.
Trimble tells me that the tool that they use to work with DWG and DXF files is the cause of the issue (or the way that they are using it), and that they will try to fix it going forwards. However if you see this issue today you can select the Block and right click and open it in the Block Editor. Select all the linework in the Block Editor view and use the Convert to Linestring Command to convert all of the line types (CAD Lines, Polylines, 3D Polylines, Multilines etc.) to Linestrings. Wen you have done that you will be able to explode the block to extract the linework into the project.
If you feel that this is happening in a dataset, do not delete the blocks after exploding them. Relayer them and hide them so that they are invisible but available and then you can use them later if you find missing data after an explode process is completed.
Hope this is helpful
Alan