Getting below error though the page is not hindering to do any DML transactions.
This page has an error. You might just need to refresh it. Error in $A.getCallback() [Assertion Failed!: Invalid container : undefined [Error creating components markup://force:previewPanel in hoverLibrary]] Failing descriptor: {force:outputLookupWithPreview}.
1. There is a dropdownlist of objects containing object names like campaign,account,opportunity and donation.
2. user selects object.
3. Enter text in multi select searchbox.
4. inside searchbox we are using lightning record view form to display compact layout fields based on the object.
5. user hits save button after selecting records from multi lookup fields.
6. records are being saved but getting error as mentioned above.
@Charles Cummings please add in case of any further information to be added.
I haven't to be honest m- I would suggest posting to the SFDX Stack Exchange (https://salesforce.stackexchange.com/) with some sample code - more likely someone there would recognize it
