Hey,
have you used an older WHMCS version with the old SolidCP WHMCS module before and have you upgraded it?
I've seen, that WHMCS deletes old legacy modules automatically since v. 7.5. But I would suppose, that they are also deactivating them before deleting. Or have you deleted the old module files before deactivating them?
The SolidCP WHMCS module only checks the following $GLOBALS variable:

$deactive_old_modules = array();
foreach($GLOBALS['activeaddonmodules'] as $value){
if($value == 'solidcp_addons') $deactive_old_modules[]='solidcp_addons';
if($value == 'solidcp_configurable') $deactive_old_modules[]='solidcp_configurable';
if($value == 'solidcp_sync') $deactive_old_modules[]='solidcp_sync';
}
if(count($deactive_old_modules)>0) return $deactive_old_modules;
else return false;

You can try two things:

• you can try to upload the old WHMCS module and then activate/deactivate it. You can find the old module here:  http://installer.solidcp.com/Files/1.0.1/plugins/SolidCP.WHMCSModule.zip . If it's successful, you can delete the old module after that.
• you can add "{debug}" to a WHMCS template and load this site. This will show you all variables. Can you check, if $GLOBALS['activeaddonmodules'] has values "solidcp_addons" and "solidcp_sync"? If yes, then these modules are still active in WHMCS, then you can ask the WHMCS support, why these modules are not shown in the module list, but still active. In the meanwhile you can try to change the needModuleDeactivation() function in /modules/addons/solidcp_module/lib/migration.php. Just replace everything in the function with "return false;" and try again if everything is working properly. Please don't forget to remove the {debug} code from your template, because with this code everyone, who visit this site can see all internal variables from WHMCS. Please note that this is only a quick workaround.

Best regards
Bogdan

Hello,
Thank you for your answer,
you can try to upload the old WHMCS module and then activate/deactivate it.
Ok i have done that, and deactivated both the modules, and now it is not showing that error, as you can see it in the screenshot below,

But now i m getting a new error when i click on products/services at the bottom , which is

Oops!
Something went wrong and we couldn't process your request.
Please go back to the previous page and try again.

exception 'WhoopsExceptionErrorException' with message 'SOAP-ERROR: Parsing WSDL: Couldn't load from 'http://theredserver.com:9002/esUsers.asmx?WSDL' : failed to load external entity "http://theredserver.com:9002/esUsers.asmx?WSDL"
' in C:DomainsBillingNewmodulesaddonssolidcp_modulelibenterpriseserver.php:519
Stack trace:
#0 C:DomainsBillingNewvendorwhmcswhmcs-foundationlibUtilityErrorRun.php(0): WHMCSUtilityErrorRun->handleError(1, 'SOAP-ERROR: Par...', 'C:\Domains\Bill...', 519)
#1 [internal function]: WHMCSUtilityErrorRun->handleShutdown()
#2 {main}

Can you tell me how to fix that?
Thank you for your reply in advance

This has been resolved.
Thank you.