We get the following error on validation:
Initial validation checks (step 1)
baseURL is https://grdspublishing.org/index.php/index/oai
Validation only
Request logged from 103.82.34.54
Checking Identify response
REQUEST Open Journal Systems GET
WARN Malformed response: syntax error at line 1, column 0, byte 0 at /usr/lib64/perl5/vendor_perl/XML/Parser.pm line 187. . The most common reason for malformed responses is illegal bytes in UTF-8 streams (e.g. the inclusion of Latin1 characters with codes>127 without creating proper UTF-8 mutli-byte sequences). You might find the utf8conditioner, found on the OAI tools page helpful for debugging.
FAIL Failed to parse Identify response
FAIL ABORT: Failed to parse Identify response from server at base URL ‘https://grdspublishing.org/index.php/index/oai’.
The OAI-PMH data provider with base URL https://grdspublishing.org/index.php/index/oai has failed initial validation. Problems reported must be corrected before validation can continue.
How to solve the problem?