Your comments

Thank you very much, it fixed the problem. So now I dont have 500 errors.

"doesn't affect any functionality"

By the way playing media files dont work, because I have 500 error.

I have also another 500 error when open media files.

"<script src="?module=fileman§ion=utils&page=custom_actions.js&language=english&v=2018.02.13"></script>"

GET https://filerun/?module=fileman§ion=utils&page=custom_actions.js&language=english&v=2018.02.13 500 (Internal Server Error)

Now I have another 500 error when open media files.

min.php?v=2018.02.13:4070 POST https://filerun/?module=fileman§ion=utils&page=file_preview 500 (Internal Server Error)
FR.UI.postToTarget @ min.php?v=2018.02.13:4070
FR.components.ImageViewer.Ext.extend.loadHiRes @ min.php?v=2018.02.13:5822
r @ min.php?extjs=1&v=2018.02.13:2
setInterval (async)
n.delay @ min.php?extjs=1&v=2018.02.13:2
loadFile @ min.php?v=2018.02.13:5914
setFile @ min.php?v=2018.02.13:5939
open @ min.php?v=2018.02.13:5974
showPreview @ min.php?v=2018.02.13:4402
openItem @ min.php?v=2018.02.13:2121
rowdblclick @ min.php?v=2018.02.13:1985
fire @ min.php?extjs=1&v=2018.02.13:2
fireEvent @ min.php?extjs=1&v=2018.02.13:2
processEvent @ min.php?extjs=1&v=2018.02.13:2
processEvent @ min.php?extjs=1&v=2018.02.13:2
onDblClick @ min.php?extjs=1&v=2018.02.13:2
S @ min.php?extjs=1&v=2018.02.13:2

 I also found "PHP Warning:  sizeof(): Parameter must be an array or an object that implements Countable in C:\inetpub\filerun_storage\system\classes\vendor\FileRun\Lang.php on line 207"

Thank you, I found the error. I had filetypes.php file encoded using ionCube for older PHP version. And in your guide you dont mention to replace it.

The board always changes the URL to an example like above, so I add a space "module=fileman& section=get&page=grid"

Thank you for additional information. I had checked /advanced_configuration before but didn't found this parameter there. So it would be good to add it.

For my case (100Mbps & 20MB chunk size) the upload speed difference is 2 times, I think it is not accurate at all =)

PS: I dont know why, but each time I am logging in here my name is flushed to a default one.

"I didn't set limits that can influence such behavior (actual limits much higher everywhere). So it means that this setting is somewhere in FileRun."

- I wouldn't create a new topic if it was because of "upload_max_filesize" and "post_max_size" settings. I tried different settings from 8M to 500M. And behavior is the same when it is set to 20M+! If it is set less then 20M, so it gets stuck earlier. My IIS web-server doesn't have upload file size limits anywhere as well. I've checked it.

So I want a solution that can resolve this quite critical issue.

I think it would be good to create 2 temp files for each uploading file. So when it is moving to the final destination it is still uploading the next chunk.

PS: You said nothing about uploading speed indication issue that I've mention before.

PS2: I posted as Anonymous by mistake, please delete it.