unable to get BIP Excel output and ends with error file format and extension dont match

Summary:

when BIP Excel output is generated, the xls output ends with an error as

"the file format and extension 'filename.xls' dont match.

when the dialogue button is accepted, it opens with non readable excel output.

data appears when the report is viewed within the BIP excel template as view report.

Content (please ensure you mask any confidential information):

Version (include the version you are using, if applicable):

12.2.6.4.0

Code Snippet (add any code snippets that support your topic, if applicable):