In the below query after adding date condition the query returns error - Cannot complete this action. Please try again..
"<View><Query><Where><And><Eq><FieldRef Name='Company' /><Value Type='Text'>" + CompanyName + "</Value></Eq>" +
"<And><Eq><FieldRef Name='License' /><Value Type='Text'>" + License + "</Value></Eq>" +
"<And><Eq><FieldRef Name='Active' /><Value Type='Boolean'>0</Value></Eq> <IsNull><FieldRef Name='ReplacementUserID'/></IsNull >" +
"<And><Geq><FieldRef Name='LicenseExpiryDate'/><Value IncludeTimeValue='FALSE' Type='DateTime'><Now /></Value></Geq>" +
"</And></And></And></And></Where></Query><RowLimit>100</RowLimit></View>"
<And>
before<IsNull><FieldRef Name='ReplacementUserID'/>
or add closing</And>
after that condition (as per your requirements/conditions). You are doing it wrong here.