Retrieve Email Messages action throwing error

[Anonymous]

I'm using the Retrieve Email Messages flow action in my PAD flow and it continuous to throw this error, "Failed to retrieve message with uid 1853". This is a similar issue to the one described in this post: https://powerusers.microsoft.com/t5/Power-Automate-Desktop/Retrieve-Email-Messages-returns-weird-err...

This is really frustrating. I'm not entirely sure why but this Flow is experiencing this issue in isolation. I have several carbon copies of this Flow with only minor changes to the actions, the most dramatic change being the "To" address the Retrieve Email Messages action looks for when performing - as well as changing the target folder path via a variable. Changing the folder path variable once changes the target folder throughout the flow.

Like I stated, I have other flows composed of the exact same actions with the primary difference being where the files are being placed and which email address is being used to filter the email messages with.

Here's the raw error information:

Index (zero based) must be greater than or equal to zero and less than the size of the argument list.: Microsoft.Flow.RPA.Desktop.Modules.SDK.ActionException: Failed to retrieve message with uid 1853. ---> System.FormatException: Index (zero based) must be greater than or equal to zero and less than the size of the argument list.
at System.Text.StringBuilder.AppendFormatHelper(IFormatProvider provider, String format, ParamsArray args)
at System.String.FormatHelper(IFormatProvider provider, String format, ParamsArray args)
at System.String.Format(String format, Object arg0)
at Microsoft.Flow.RPA.Desktop.Modules.Email.Actions.EmailActions.RetrieveEmails(Variant imapServer, Variant username, Variant varPassword, Variant mailFolder, Variant fromContains, Variant toContains, Variant subjectContains, Variant bodyContains, Variant sentSince, Variant sentUpTo, Variant saveAttachmentsInto, Variant& retrievedEmails, Int32 serverPort, Boolean enableSsl, Int32 retrieveOnlyUnread, Boolean saveAttachments, Boolean markAsRead, Boolean acceptUntrustedCertificates)
--- End of inner exception stack trace ---
at Microsoft.Flow.RPA.Desktop.Modules.Email.Actions.RetrieveEmails.Execute(ActionContext context)
at Microsoft.Flow.RPA.Desktop.Robin.Engine.Execution.ActionRunner.Run(IActionStatement statement, Dictionary`2 inputArguments, Dictionary`2 outputArguments)

I've tried the fixes @MichaelAnnis suggested in the attached post, but it's not making the Flow work anymore. I've also tried two full reboots, turn the computer all the way off, unplug, plug back in, turn on... nothing.

Some of my job is relying on this Flow's smooth operation. Arg.

Any suggestions as to what might be the cause?

****Edit:

I've built a much more condensed flow to test if PAD will throw the same or similar error for just the "To" string I supply.

It works, but now the Retrieve Email Messages behavior is way out of wack. I have it set to retrieve only read emails, and to only gather emails with a string in the "To" field. There's only 1 email that meets criteria of 9 total emails. Each run the Flow will wrongly grab EVERY email, not just the 1 qualifying email. If I change only the "To" field string, it behaves as normal and retrieves only the correct email. If I change the "To" string back to my desired target, it retrieves EVERY email.

In my primary flow, the one throwing the uid 1853 error, I can change the "To" field to anything other than my target string and it will work correctly.

Arg!

[MichaelAnnis]

This part should be an easy fix, if you see what is causing this error:

"Index (zero based) must be greater than or equal to zero and less than the size of the argument list."

I have also seen "TO" field fail if you are trying to search for a distribution list.  For instance:

Retrieve emails with the TO field Team_DistributionList@domain.com.

The problem with this is if you were to look at the .'[To]' property of this email, it is not as simple as "Team_DistributionList@domain.com".  It is some long, crappy text that is not very readable.  I have had to bypass these and use alternative methods to narrow them down.

[Anonymous]

These emails originally came from a Power Automate Web Flow. The email result is built by getting the User Profile email account string and turning that into a variable. That should just be a normally formatted string, tho, right?

Any suggestions for work arounds? This is really really frustrating me. LOL!

[Anonymous · Accepted solution]

Troubleshooting guide:

If your Retrieve email messages Flow action is not retrieving anything at all and fails upon running there's something behind the scenes that's gone sour. PAD does not store all of its necessary tidbits on the machine running the PAD instance. PAD downloads the Flow from a server. If there's an issue with the stored PAD Flow you'll always pull out the same issue when running the Flow.

First try turning PAD on and off again.

Next try turning the machine on and off again, full reboot. Let it power down completely and then power back on after about 5 minutes of down-time.

If the issue persists, next try uninstalling/reinstalling PAD.

If the issue still persists, next try reviewing your Data Connections in your Office 365 account controls. Office Portal -> Power Automate -> Data -> Connections -> Create connection to Outlook

If the problem persists follow the below steps:

Create a new Flow from the PAD window. Name your Flow something useful. In your new Flow, create the following actions:

1. Launch Outlook

2. Retrieve email messages

3. Close Outlook

4. Display message w/ %RetrievedEmails% in the body text.

Set up your Retrieve email messages action to dispense every email in your inbox folder. In the Retrieve email messages action email filters options: "Mail folder:" should read "Inbox" (no quotes) for just inbox messages. If this does not work, you'll need to contact Microsoft support for more help. If this works, continue reading. Narrow your target down towards your goal. Mine is to get into a subfolder and retrieve particular emails based on some criteria. Next either target a subfolder "Inbox/yoursubfolder" or modify the "to contains", "from contains", etc, fields one at a time. Continue to run your Flow after each modification. If your Flow fails to retrieve anything with your particular needs, you will likely need to contact Microsoft support. If your Flow succeeds and your message box displays all of your desired information you've successfully overcome whatever hang-up was in your previous problem-Flow.

Once your new Flow is working as intended you can now open your problem-Flow and copy/paste the other Flow actions into/around the new Retrieve email messages Flow actions. Keep in mind however that changes to directory paths or file structure will need to be reflected in the Flow actions.

Hope this helps anyone. I've been battling this issue about 3 times now, each time it's a little more particular.