Please tell us the exact wording of the error message, or even better, post a screenshot of it.
Also, what version of LR, and what operating system.
How many photos are you exporting at a time?
Have you tried exporting in batches, like 100 at a time?
And how much RAM does your computer have?
There are 1233 photos I'm trying to export all at once. I have not tried doing in batches.. I guess I never thought of that! I've always exported full wedding galleries all in one shot (more photos than that as well) and never had a problem until yesterday. I'm currently trying to export them all to a folder on my desktop rather than the external hard drive I was originally exporting to. Here are my computer specs, I have 8gb of memory and 1TB of storage on my startup disk
8 GB RAM is considered the minimum to run Lightroom properly, and should be enough in most situations.
But exporting 1233 photos is a big task, and I guess you could be running out of RAM, although you would normally get a different error message, saying just that.
What you could try is to restart your computer, and then try the export with no other programs than Lightroom running.