Apparently it is possible that we only have a suggested edit queue of 40 edits:
What's the fixed size of the suggested edit queue? tells us that we only have 40 edits pending at a time. While there are currently on 35 edits waiting for review you may have hit it when there were 40 edits pending.
An alternative issue...
New editors can have at most 5 pending edits. Until those edits are approved you will not be able to submit new edits.
All you can do is wait for people to review the edits and approve or reject them.