Hi all.
I wanted to sort all my block by categorie, but that does not work. By searching the cause I tried to delete all blocks. (in an test-copy 
)
After that many blocks left causing red and yellow errors. Redoing diminues the number of blocks, but at one point an internal error arrived.
I deleted all blocks manually, having an empty workplace but still having errors!!
then made an aia file - moved to trash - deleted in trash 
then imported the test.aia and I saw there are still some block which arrived to be visible now.
I tried other method. deleting a procedure and also it arrived getting these lost blocks and mayby hidden blocks
maybe these hidden blocks also prevent my block workplace to execute the sort all blocks command.