When opening DWG files, there are error messages that certain SHX files are missing. There is no information about how that SHX file was used in the drawing. Text and linestyles that use that SHX will not display correctly, however, that change may not be obviously apparent. It would be very helpful if the error message would include what setting/definition is using the file "not found" so that auditing DWG files for proper display could be easily addressed.
The only other option is to visually inspect every element in the drawing to ensure that everything displays correctly.