Help Generates No Topics

I’ve been using structured (DITA1.2) FM11 w RH10 about five years with no issues until mid Dec where it crashed for one of 3 versions. The largest ditamap crashed, FM runs out of memory or generates No Topics. Nearly 900 Topics. All elements are valid. I took the entire ditamap and published each section at a time hoping to find the breaking point but each section publishes successfully. When I comment out one section, section X, the entire help except for section X generates. When I comment out everything except for section X, section X generates  help. Have I reached a file size limit? Are my settings off, could I have clicked a control

or flipped a flag somewhere?

I had TCS2017 on the shelf, and I upgraded and it will generate the help in section but not the entire file.

Adobe Support suspects a file in the ditamap is corrupt but that can’t be the case because all of the files work when I publish the files in smaller sections. The same files are in the user guides, and those generate.

In the last run no help generated and I got new error; error in generating Help TOC.error -  I got this after resetting the templates to the initial out of the box templates.

Any help/ideas/direction is greatly appreciated!