Since SharePoint maintains its own set of rules for file maintenance and modification, it is necessary to perform the following steps to delete/upgrade the deployed DevExpress Web Parts.
Back up HTML content of the HtmlEditor-based Web Parts (if any):
1) Edit the corresponding page via the Site Actions -> Edit Page command.
2) Edit the HtmlEditor-based Web Parts via the Smart Tag's Edit Web Part command.
3) Copy and store the HTML content from the HTML tab.
Remove DevExpress Web Parts from all pages:
1) Edit the corresponding page via the Site Action -> Edit Page command.
2) Select the required Web Part.
3) Click the Delete command within the Smart Tag menu.
Deactivate the DevExpress Features via the Site Actions -> Site Settings -> Manage Site Features menu).
Stop the "SharePoint 20XX Administration" service.
Unregister DevExpress SharePoint Web Parts via the ASPxSharePointRegister.exe tool (use the same version as the DevExpress assemblies).
Ensure that there are no DevExpress entries in the Web.config file.
Clear the corresponding "Temporary ASP.NET Files" directory (the C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Temporary ASP.NET Files\ path for SharePoint 2013 and SharePoint 2016). This may require stopping the IIS process via the following command.
Restart IIS using the following command.
Examine the problematic pages and check to see if they operate properly, and there are no errors or warning messages.
Install the new version of DevExpress SharePoint Web Parts. Refer to the following article to learn how to install DevExpress SharePoint Web Parts: Installation.
Activate the required DevExpress feature.
Insert the required Web Part into the required page.
Restore the backup HTML content (if any).
Examine the corresponding pages and check to see if they operate properly and there are no errors or warning messages.