diff --git a/docs/PHP/danog/MadelineProto/RPCError/ChannelInvalidError.md b/docs/PHP/danog/MadelineProto/RPCError/ChannelInvalidError.md
new file mode 100644
index 0000000000..3646c60eac
--- /dev/null
+++ b/docs/PHP/danog/MadelineProto/RPCError/ChannelInvalidError.md
@@ -0,0 +1,99 @@
+---
+title: "danog\\MadelineProto\\RPCError\\ChannelInvalidError: The provided channel is invalid."
+description: "\nNote: this exception is part of the raw API, and thus is not covered by the backwards-compatibility promise.\n\nAlways check the changelog when upgrading, and use tools like Psalm to easily upgrade your code.\n"
+image: "https://docs.madelineproto.xyz/favicons/android-chrome-256x256.png"
+parent: "MadelineProto API"
+
+---
+# `danog\MadelineProto\RPCError\ChannelInvalidError`
+[Back to index](../../../index.html)
+
+> Author: Daniil Gentili <daniil@daniil.it>  
+  
+
+The provided channel is invalid.  
+
+
+Note: this exception is part of the raw API, and thus is not covered by the backwards-compatibility promise.
+
+Always check the changelog when upgrading, and use tools like Psalm to easily upgrade your code.
+
+
+## Properties
+* `$rpc`: `string` RPC error.
+* `$description`: `string` Human-readable description of RPC error.
+* `$tlTrace`: `string` TL trace.
+
+## Method list:
+* [`getLocalization(): string`](#getLocalization)
+* [`getMessage(): string`](#getMessage)
+* [`getCode()`](#getCode)
+* [`getFile(): string`](#getFile)
+* [`getLine(): int`](#getLine)
+* [`getTrace(): array`](#getTrace)
+* [`getPrevious(): ?Throwable`](#getPrevious)
+* [`getTraceAsString(): string`](#getTraceAsString)
+* [`getTLTrace(): string`](#getTLTrace)
+
+## Methods:
+### <a name="getLocalization"></a> `getLocalization(): string`
+
+Get localized error name.
+
+
+
+### <a name="getMessage"></a> `getMessage(): string`
+
+
+
+
+
+### <a name="getCode"></a> `getCode()`
+
+
+
+
+
+### <a name="getFile"></a> `getFile(): string`
+
+
+
+
+
+### <a name="getLine"></a> `getLine(): int`
+
+
+
+
+
+### <a name="getTrace"></a> `getTrace(): array`
+
+
+
+
+
+### <a name="getPrevious"></a> `getPrevious(): ?Throwable`
+
+
+
+
+#### See also: 
+* `Throwable`
+
+
+
+
+### <a name="getTraceAsString"></a> `getTraceAsString(): string`
+
+
+
+
+
+### <a name="getTLTrace"></a> `getTLTrace(): string`
+
+Get TL trace.
+
+
+
+---
+Generated by [danog/phpdoc](https://phpdoc.daniil.it)
diff --git a/docs/PHP/index.md b/docs/PHP/index.md
index 3bab36d713..2323e22b8b 100644
--- a/docs/PHP/index.md
+++ b/docs/PHP/index.md
@@ -342,6 +342,7 @@ Async PHP client API for the telegram MTProto protocol.
 * [\danog\MadelineProto\RPCError\ButtonUserPrivacyRestrictedError: The privacy setting of the user specified in a [inputKeyboardButtonUserProfile](/constructor/inputKeyboardButtonUserProfile) button do not allow creating such a button.](/PHP/danog/MadelineProto/RPCError/ButtonUserPrivacyRestrictedError.html)
 * [\danog\MadelineProto\RPCError\CallAlreadyAcceptedError: The call was already accepted.](/PHP/danog/MadelineProto/RPCError/CallAlreadyAcceptedError.html)
 * [\danog\MadelineProto\RPCError\CallAlreadyDeclinedError: The call was already declined.](/PHP/danog/MadelineProto/RPCError/CallAlreadyDeclinedError.html)
+* [\danog\MadelineProto\RPCError\ChannelInvalidError: The provided channel is invalid.](/PHP/danog/MadelineProto/RPCError/ChannelInvalidError.html)
 * [\danog\MadelineProto\RPCError\ChannelPrivateError: You haven't joined this channel/supergroup.](/PHP/danog/MadelineProto/RPCError/ChannelPrivateError.html)
 * [\danog\MadelineProto\RPCError\ChatAdminRequiredError: You must be an admin in this chat to do this.](/PHP/danog/MadelineProto/RPCError/ChatAdminRequiredError.html)
 * [\danog\MadelineProto\RPCError\ChatForbiddenError: This chat is not available to the current user.](/PHP/danog/MadelineProto/RPCError/ChatForbiddenError.html)
diff --git a/docs/docs/DOCKER.md b/docs/docs/DOCKER.md
index bfd3aff792..3ca8703cdd 100644
--- a/docs/docs/DOCKER.md
+++ b/docs/docs/DOCKER.md
@@ -32,6 +32,15 @@ echo 262144 | sudo tee /proc/sys/vm/max_map_count
 echo vm.max_map_count=262144 | sudo tee /etc/sysctl.d/40-madelineproto.conf
 ```
 
+Then, increase the maximum open FD limit, to allow opening many TCP sockets for improved upload and download performance and avoid errors.  
+
+```php
+sudo mkdir -p /etc/security/limits.d/
+
+echo '* soft nofile 1048576' | sudo tee -a /etc/security/limits.d/40-madelineproto.conf
+echo '* hard nofile 1048576' | sudo tee -a /etc/security/limits.d/40-madelineproto.conf
+```
+
 Finally, follow one or more of the following guides, according to your needs:
 
 ### CLI bot (recommended)
diff --git a/docs/docs/REQUIREMENTS.md b/docs/docs/REQUIREMENTS.md
index 366b91f079..5454b7dfeb 100644
--- a/docs/docs/REQUIREMENTS.md
+++ b/docs/docs/REQUIREMENTS.md
@@ -44,6 +44,11 @@ echo ffi.enable=1 | sudo tee $(php --ini | sed '/additional .ini/!d;s/.*: //g')/
 echo 262144 | sudo tee /proc/sys/vm/max_map_count
 echo vm.max_map_count=262144 | sudo tee /etc/sysctl.d/40-madelineproto.conf
 
+sudo mkdir -p /etc/security/limits.d/
+
+echo '* soft nofile 1048576' | sudo tee -a /etc/security/limits.d/40-madelineproto.conf
+echo '* hard nofile 1048576' | sudo tee -a /etc/security/limits.d/40-madelineproto.conf
+
 cd /tmp
 sudo apt-get install build-essential
 git clone https://github.com/danog/PrimeModule-ext
@@ -51,6 +56,6 @@ cd PrimeModule-ext && make -j$(nproc) && sudo make install
 
 ```
 
-The `max_map_count` sysctl configuration is required to avoid "Fiber stack allocate failed" and "Fiber stack protect failed" errors, since the PHP engine mmaps two memory regions per fiber.  
+The `max_map_count` sysctl configuration is required to avoid "Fiber stack allocate failed" and "Fiber stack protect failed" errors, since the PHP engine mmaps two memory regions per fiber, and the `soft/hard nofile` limits increase the maximum open FD limit, to allow opening many TCP sockets for improved upload and download performance, and to avoid errors.  
 
 <a href="https://docs.madelineproto.xyz/docs/DOCKER.html">Next section</a>
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