Unable to map file name (containing uppercase & digit) to domain name

[savaliyagautam]

In documentation of under Mapping of file paths to domain names it says

For path names that include non-alphanumeric charters, replace any such characters with the string ‘%XX’ where XX is the hexidecimal value of the character.

I assumed that numeric characters in a filename are valid.

• When I tried to map Filename2017_100.h5 with my domain to filename2017_100.mydomain, it gave me 500 response.
• When I removed numeric value from file name like filename_test.h5, it successfully mapped to filename_test.mydomain.

Not sure If I am missing something else. Is there a way to map domain name with a filename containing upper case and digit?