I'm using mediawiki 1.35 on Ubuntu 20.04 LTS. Problems occur when using Visual Editor. A document of a typical length works well, but if the document contains a lot of sentences or is excessively long, the following occurs:
(1) When switching from original to visual editing, the progress bar stops near 75%.
(2) After a few seconds, the message Error contacting the Parsoid/RESTBase server: (curror: 28) Timeout was read.
I tested my wiki's error-prone document with Wikipedia, and (1) went as it was, but successfully switched to visual editing.
I googled for hours and tested various tests, but it didn't work.
my wiki uses iptime DDNS and also has normal access to http://MyPrivateWikiDDNS.org/mediawiki/rest.php/MyPrivateWikiDDNS.org/v3/page/html/Main_Page. It's also a Private Wiki. The installation document says RESTBase should not be used on the Private Wiki, so I didn't use it. I need your help.
Thank you.