Maybe helpful, if having trouble connecting to the AP via cnMaestro or http/https, you can also download/export the tech-support dump file via CLI and transfer it to a TFTP or FTP server:
E410-04F292-Office(config)# export tech-support
a TFTP or FTP server path (Eg: tftp://1.2.3.4/tech.tar.gz, ftp://user:pass@1.2.3.4/tech.tar.gz)
E410-04F292-Office(config)# export tech-support ftp://admin:admin@172.20.99.99/tech.tar.gz