In T269673#6676137, @ti_infotrad wrote:

The following code seems to be fixing it.

E:\Websites\mediawiki-1.35.0>git diff extensions/VisualEditor/includes/VEParsoid/src/Rest/Handler/ParsoidHandler.php
warning: LF will be replaced by CRLF in extensions/VisualEditor/includes/VEParsoid/src/Rest/Handler/ParsoidHandler.php.
The file will have its original line endings in your working directory
diff --git a/extensions/VisualEditor/includes/VEParsoid/src/Rest/Handler/ParsoidHandler.php b/extensions/VisualEditor/includes/VEParsoid/src/Rest/Handler/ParsoidHandler.php
index 649a9aa3..e706aaa7 100644
--- a/extensions/VisualEditor/includes/VEParsoid/src/Rest/Handler/ParsoidHandler.php
+++ b/extensions/VisualEditor/includes/VEParsoid/src/Rest/Handler/ParsoidHandler.php
@@ -338,6 +338,8 @@ abstract class ParsoidHandler extends Handler {
                string $title, ?int $revision, string $wikitextOverride = null,
                string $pagelanguageOverride = null
        ): PageConfig {
+               $title = utf8_encode($title);
                $title = $title ? Title::newFromText( $title ) : Title::newMainPage();
                if ( !$title ) {
                        // TODO use proper validation