In local MampPro setup, attempted to run update.php to update core to 1.18.3 but returned blank page, no progress bar shown. Looked at /admin/reports/dblog there is no error.
Tried on two separate relatively fresh test setups the update ran smoothly. One thing I noted is this problematic one I have civicrm dbase setup separately. It's the same dbase user with ID/PW root/root. php ini settings are default.
Also attempted to edit php ini template file to memory_limit = 512M; max_execution_time = 600; max_input_time = 600; post_max_size = 256M; upload_max_filesize = 256M but same blank screen.
One next thing I haven't tried is to use drush to update, but I'm still figuring out how to set this up.
What other possible areas could have caused the blank screen? Appreciate any advice. Thank you!