As PowerBuilder is designed to be case-insensitive and always uses lower cases to access the deployed folders/files, therefore, in a case-sensitive file system like Linux, folder/file names (such as theme files, images etc.) containing upper cases may not be found or loaded. To avoid such issues, you should always use lower cases in folder/file names for your application, or add the following configuration to Apache in Linux to ignore the case:
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                     Go to the /etc/httpd/conf folder, and open httpd.conf in a text editor. 
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                     Search "loadmodule" and add the following lines. Pay special attention to the words "speling_module" and "mod_speling" (not spelling). LoadModule speling_module modules/mod_speling.so CheckSpelling on 
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                     Check if any syntax error in httpd.conf. $ sudo apachectl configtest 
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                     Restart Apache. $ sudo systemctl restart httpd If Apache failed to start, go to the /var/log/httpd folder and view the error_log.log and access_log.log files to read the detailed error information. 



