Configure file size limits
File size limits in IDE properties
For performance and memory consumption reasons, JetBrains Rider sets the following file size limits:
The maximum size for files that JetBrains Rider is able to open, is controlled by the
idea.max.content.load.filesizeIDE property. The default value is20000kilobytes.The maximum size for files where JetBrains Rider enables coding assistance and design-time code inspection, is controlled by the
idea.max.intellisense.filesizeproperty. The default value is2500kilobytes.
Change the file size limits in IDE properties
Do one of the following:
Select from the main menu.
On the Welcome screen, click Configure and then select Edit Custom Properties.
If you cannot start JetBrains Rider, you can manually create an empty idea.properties file in the JetBrains Rider configuration directory.
In the custom idea.properties file that opens in a new editor tab, specify the desired values in kilobytes, for example:
idea.max.intellisense.filesize=3500The properties you add to this file override the corresponding default properties.
File size limit for design-time inspection
JetBrains Rider additionally limits the size of files where design-time inspection is enabled by default to 300 kilobytes. For larger files, the inspection is disabled to make sure such files load without delays. You can recognize files where code inspection is disabled by the 
indicator in the top right corner of the editor.
You can press Control+Alt+Shift+8 to enable inspection in the file as long as its size doesn't exceed the limit specified by the idea.max.intellisense.filesize property. JetBrains Rider will remember your choice and will not disable design-time inspection next time you open that file.