Sometimes, the CAD will not copy and paste, what is the reason for this

CAD do, sometimes things to copy files from this document to another, but can not copy and paste, said the investigation ordered by F1, sometimes in the document may, in a block, but can not copy and paste, Do not know why it

such as schematic, you want to copy and paste ..to another.Do not work.Or you can the entire schematic.Copy to choose a good point, sometimes forget that it is not
paste and sometimes more than open file, a file, there is no end of the order, so that the problem will be,
May sometimes be some hidden layers, the paste can not see them, or locked, freeze, which would
solution to the problem:a look at any of the above-mentioned problems, and then use the menu to copy (Note Election basis points), and then use the Paste menu (or paste into a block), in theory, should be no problem, I suggest you look for the CAD materials, a look, you will understand a lot of.Ha ha, I have never experienced not work.I used the CAD at least 8 years now!