Hmm..I'm playing with the latest version...
Everything else besides the lab works normally?
Viewing post in ElPresidentes Tweaks v0.3
Then it's just the laboratory.gd file. You can replace it with the backup one.
You can also do a compare to see the changes (there are only a few) and add them in manually to the fresh file. Should be easy to find (output and enlarge would be the keywords). There are 3 places in the file where an operation is defined