Calc crashes when loading document with conditional formatting

Using Calc from LibreOffice 5.1.3, but this problem has persisted since before 5.0

Calc will load and function with other documents, but there is one document that has a lot of conditional formatting - the condition is when a certain column is populated with data, then the row format changes so that the background color is different from default. This worked OK at first, but as the size of the document increased, file load time increased, and eventually failed, with this error message:

Fatal Error
Service not supplied: loading component library {file:///C://Program Files (x86)/LibreOffice 5/program/…/program/mergedlo.dll} failed

The document size is approximately 2400 rows x 30 columns 1.05 MB

Is this fixable at the program level, or do I need to rebuild the document without conditional formatting?

This is a serious data loss error. Is nobody interested?

The document was rebuilt to exclude the conditional formatting. File size decreased to 300KB. Load time when opening and closing the file decreased a lot. The data is now accessible for work.

It seems that conditional formatting is too resource intensive, except for limited use.