We had similar problem after updating to ES 9.6.100. Found that we had customized the macapprechk report in crystal version 11. This causes issues, we needed to change the custom database connection, re-map fields, and fix a few formulas before getting it to work.
See Document: 23.709.392 - Macola ES version ES9.5.800 - Changing the Custom Database Connection for Crystal Reports
Good luck.