everysync for ie "application is improperly formatted"

Can no longer install Eversync IE client. Get pop-up:

Details reveals:

PLATFORM VERSION INFO
Windows : 10.0.16299.0 (Win32NT)
Common Language Runtime : 4.0.30319.42000
System.Deployment.dll : 4.7.2556.0 built by: NET471REL1
clr.dll : 4.7.2633.0 built by: NET471REL1LAST_C
dfdll.dll : 4.7.2556.0 built by: NET471REL1
dfshim.dll : 10.0.16299.15 (WinBuild.160101.0800)

SOURCES
Deployment url : https://everhelper.me/ie/EverSyncIE.application

ERROR SUMMARY
Below is a summary of the errors, details of these errors are listed later in the log.
* Activation of https://everhelper.me/ie/EverSyncIE.application resulted in exception. Following failure messages were detected:
+ Exception reading manifest from https://everhelper.me/ie/EverSyncIE.application: the manifest may not be valid or the file could not be opened.
+ Manifest XML signature is not valid.
+ The digital signature of the object did not verify.

COMPONENT STORE TRANSACTION FAILURE SUMMARY
No transaction error was detected.

WARNINGS
There were no warnings during this operation.

OPERATION PROGRESS STATUS
* [4/27/2018 11:27:04 AM] : Activation of https://everhelper.me/ie/EverSyncIE.application has started.

ERROR DETAILS
Following errors were detected during this operation.
* [4/27/2018 11:27:05 AM] System.Deployment.Application.InvalidDeploymentException (ManifestParse)
- Exception reading manifest from https://everhelper.me/ie/EverSyncIE.application: the manifest may not be valid or the file could not be opened.
- Source: System.Deployment
- Stack trace:
at System.Deployment.Application.ManifestReader.FromDocument(String localPath, ManifestType manifestType, Uri sourceUri)
at System.Deployment.Application.DownloadManager.DownloadDeploymentManifestDirectBypass(SubscriptionStore subStore, Uri& sourceUri, TempFile& tempFile, SubscriptionState& subState, IDownloadNotification notification, DownloadOptions options, ServerInformation& serverInformation)
at System.Deployment.Application.DownloadManager.DownloadDeploymentManifestBypass(SubscriptionStore subStore, Uri& sourceUri, TempFile& tempFile, SubscriptionState& subState, IDownloadNotification notification, DownloadOptions options)
at System.Deployment.Application.ApplicationActivator.PerformDeploymentActivation(Uri activationUri, Boolean isShortcut, String textualSubId, String deploymentProviderUrlFromExtension, BrowserSettings browserSettings, String& errorPageUrl, Uri& deploymentUri)
at System.Deployment.Application.ApplicationActivator.PerformDeploymentActivationWithRetry(Uri activationUri, Boolean isShortcut, String textualSubId, String deploymentProviderUrlFromExtension, BrowserSettings browserSettings, String& errorPageUrl)
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Deployment.Application.ApplicationActivator.PerformDeploymentActivationWithRetry(Uri activationUri, Boolean isShortcut, String textualSubId, String deploymentProviderUrlFromExtension, BrowserSettings browserSettings, String& errorPageUrl)
at System.Deployment.Application.ApplicationActivator.ActivateDeploymentWorker(Object state)
--- Inner Exception ---
System.Deployment.Application.InvalidDeploymentException (SignatureValidation)
- Manifest XML signature is not valid.
- Source: System.Deployment
- Stack trace:
at System.Deployment.Application.Manifest.AssemblyManifest.ValidateSignature(Stream s)
at System.Deployment.Application.ManifestReader.FromDocument(String localPath, ManifestType manifestType, Uri sourceUri)
--- Inner Exception ---
System.Security.Cryptography.CryptographicException
- The digital signature of the object did not verify.

- Source: System.Deployment
- Stack trace:
at System.Deployment.Internal.CodeSigning.SignedCmiManifest.Verify(CmiManifestVerifyFlags verifyFlags)
at System.Deployment.Application.Manifest.AssemblyManifest.ValidateSignature(Stream s)

COMPONENT STORE TRANSACTION DETAILS
No transaction information is available.