When creating database documentation in Compiled HTML Help (CHM) format, the following error may occur:
Assertion failure: (pszTmp == m_pCompiler->m_pHtmlMem->psz).

There is a limitation on the index size acceptable by Microsoft HTML Help Studio, which SQL Doc uses to create the CHM file. Once the index grows past 3300 entries, HTML Help Studio crashes with this error. Since this software has been supplied by Microsoft, we can't resolve the issue.

Workarounds

One possible workaround is to include fewer databases or fewer database objects in the database documentation.

The other possibility is to manually trim the index. SQL Doc should leave all of the CHM source files in the same folder that you have chosen as the output location, in a subfolder whose name contains "_src_".
Open the SQLDoc.hhk file and trim it by removing all text between <LI><OBJECT> and </OBJECT> for each node that you want to exclude from the index. After you have trimmed the index, you may attempt to compile the project manually using Microsoft HTML Workshop.