Unable to start worker thread on nginx 1.13

[intelbg]

Hello, I am using the nginx 1.13 with the following page speed configuration which is in pagespeed.conf and around 10 users has include pagespeed.conf in their vhosts:

pagespeed on; pagespeed FileCachePath /tmp/pagespeed; pagespeed DisableRewriteOnNoTransform off; pagespeed PreserveUrlRelativity on; pagespeed RespectVary on; location ~ ".pagespeed.([a-z].)?[a-z]{2}.[^.]{10}.[^.]+" { add_header "" ""; } location ~ "^/pagespeed_static/" { } location ~ "^/ngx_pagespeed_beacon$" { } pagespeed FetchHttps enable; pagespeed EnableFilters extend_cache; pagespeed RewriteLevel CoreFilters; pagespeed FetchHttps enable,allow_self_signed; pagespeed FetchHttps enable,allow_unknown_certificate_authority; pagespeed FetchHttps enable,allow_certificate_not_yet_valid; pagespeed SslCertDirectory /usr/local/nginx/ssl/;

2019/03/05 18:11:18 [alert] 3622345#3622345: worker process 3630118 exited with fatal code 2 and cannot be respawned

This is the log from nginx error_log as when I changed pagespeed from on to off it worked: 2019/03/05 17:51:57 [emerg] 3616007#3616007: setuid(99) failed (11: Resource temporarily unavailable) 2019/03/05 17:52:00 [alert] 3615950#3615950: cache manager process 3616006 exited with fatal code 2 and cannot be respawned 2019/03/05 17:52:33 [error] 3615960#3615960: [ngx_pagespeed 1.13.35.2-0] [0305/175233:ERROR:worker.cc(127)] Unable to start worker thread

I saw related themes but no solutions and this is the first time I see it only on one server. Can you please give me advice what can be the reason?