I've been using OpenTBS for the past year with PHP/MySQL to merge data into an MS Word DOCX document with no problems. I populate 2-3 large nested arrays as merge blocks and the resulting Word document is 50+ pages long. Performance has never been an issue.
Recently I seem to have reached some limit as the size of data to merge has increased. There are no errors when debugging, but I get a blank PHP page instead of downloading a DOCX file. Initially, I thought there may be some characters in the data that needed escaping, but that's not the case, and if I remove (any) 5 records from any sequence in the MySQL table used for the main merge block, it works again and I get a 60 page Word document downloaded.
I am currently using OpentTBS v1.9.8. Any ideas on what is causing this?