Wordpress LScache Plugin: Failed to communicate with LiteSpeed IAPI server: no auth_key
Last Updated on: Wed, 15 Apr 2026 00:00:02 I am receiving an error when attempting to connect the Image Optimization -feature. Error: IAPI Error hash does not match: ClientCB[ ufeffJqd3PGKDBh8jJ1JL] Server[Jqd3PGKDBh8jJ1JL] Failed to communicate with LiteSpeed IAPI server: no auth_key It seems like the installation wont connect properly to the LiteSpeed web server. Is this correct? This regards the domain https://lightsheep.no but I know about a few more on the same host which experience this issue, are you able to check what could be wrong? We have debugged, verified that everything is up and running, both from the client and web server pages. If you would need any reports, access or anything, please inform me. The page I need help with: https://lightsheep.no Hello, Please post the report number. I see extra characters ( ufeff at the beginning of the cliencb). Can you check you htaccess and rewrite rules in general that can trigger there extra characters. Report number: SONHTYFR Report date: 01/22/2018 14:57:40 (Got the same error when clicked Send to LiteSpeed: IAPI Error hash does not match: ClientCB[ ufeff0vV3bGOmaJYznK0J] Server[0vV3bGOmaJYznK0J] ) The HTACCESS has the standard code for Litespeed, WordPress and WordFence. Can you try temporarily turn off WordFence to see if its caused by some rule in it? Disabled. Emtied cache, removed the fields from WordFence in .htaccess, still the same issue. IAPI Error hash does not match: ClientCB[ ufeffa7NI66xidAgkBKI3] Server[a7NI66xidAgkBKI3] Failed to communicate with LiteSpeed IAPI server: no auth_key ? I enabled it again now as its critical to keep active. If you want, I can give you access to the site to check. How about the other plugins? Can you turn them off one by one to try? Hi! When disabling ALL plugins other than litespeed, it still does not work. As I can see, the hit/cache status is not either correct for this installation. I checked the firewall (server side), there is also no rules stopped here. Hello, Can you active debug (from litespeed cache -> settings -> debug) and check some pages from your site. Yes, example: 01/24/18 13:44:35.026 [63.143.42.245:45601 1 4n9] HEAD HTTP/1.1 / 01/24/18 13:44:35.026 [63.143.42.245:45601 1 4n9] Query String: 01/24/18 13:44:35.373 [63.143.42.245:45601 1 4n9] X Cache_control init on 01/24/18 13:44:35.375 [63.143.42.245:45601 1 4n9] X Cache_control off - not GET method:HEAD 01/24/18 13:44:35.375 [63.143.42.245:45601 1 4n9] X Cache_control -> no Cache 01/24/18 13:44:35.375 [63.143.42.245:45601 1 4n9] Router: get_uid: 0 01/24/18 13:44:35.375 [63.143.42.245:45601 1 4n9] Router: get_role: 01/24/18 13:44:35.376 [63.143.42.245:45601 1 4n9] Router: role: guest 01/24/18 13:44:35.376 [63.143.42.245:45601 1 4n9] Vary: role id: failed, guest 01/24/18 13:44:35.376 [63.143.42.245:45601 1 4n9] X-LiteSpeed-Cache-Control: no-cache 01/24/18 13:44:35.376 [63.143.42.245:45601 1 4n9] Optimizer bypass: Not frontend HTML type 01/24/18 13:44:35.376 [63.143.42.245:45601 1 4n9] End response Please create a ticket for further help. For anyone else who may stumble upon this thread, there is a wiki to explain how to fix this now.
LiteCache Rush: Speed comes from using less, not from doing it faster
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