When I try to create a page using Visual Editor that has either : or / in the title I get an error: **Error contacting the Parsoid/RESTBase server (HTTP 404)**
Debugging the warning emitted in file ApiParsoidTrait.php line 160 I get the following values (when I try to create /User:John/Testpage):
```
'code':
404
'trace':
#0 /var/www/html/w/extensions/VisualEditor/includes/ApiVisualEditor.php(67): ApiVisualEditor->requestRestbase(Object(Title), 'POST', 'transform/wikit...', Array)
#1 /var/www/html/w/extensions/VisualEditor/includes/ApiVisualEditor.php(251): ApiVisualEditor->parseWikitextFragment(Object(Title), 'testtext', false, NULL, true)
#2 /var/www/html/w/includes/api/ApiMain.php(1593): ApiVisualEditor->execute()
#3 /var/www/html/w/includes/api/ApiMain.php(529): ApiMain->executeAction()
#4 /var/www/html/w/includes/api/ApiMain.php(500): ApiMain->executeActionWithErrorHandling()
#5 /var/www/html/w/api.php(90): ApiMain->execute()
#6 /var/www/html/w/api.php(45): wfApiMain()
#7 {main}
'response':
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> <html><head> <title>404 Not Found</title> </head><body> <h1>Not Found</h1> <p>The requested URL was not found on this server.</p> <hr> <address>Apache/2.4.38 (Debian) Server at localhost Port 80</address> </body></html>
'requestPath':
transform/wikitext/to/html/User%3AJohn%2FTestpage
```
What looks strange to me is this part:
```
'requestPath': transform/wikitext/to/html/User%3AJohn%2Ftestpage
```
given that some / are sanitized and some are not. So what I did is the function remove the function urlencode from lines 230 & 250 in file ApiParsoidTrait.php it then Visual Editor creates the new page without problem.
i.e. the use of urlencode there seems to create problems.