rzc generate exited with code 129

## Environment data
VS Code version: 1.50.1
C# Extension version: 1.23.4

## OmniSharp log
```
[info]: OmniSharp.MSBuild.ProjectManager
Queue project update for '/path/to/Redacted.Project.csproj'
[info]: OmniSharp.MSBuild.ProjectManager
Loading project: /path/to/Redacted.Project.csproj
[fail]: OmniSharp.MSBuild.ProjectLoader
rzc generate exited with code 129.
[warn]: OmniSharp.MSBuild.ProjectManager
Failed to load project file '/path/to/Redacted.Project.csproj'.
/path/to/Redacted.Project.csproj
/Library/Frameworks/Mono.framework/Versions/6.12.0/lib/mono/msbuild/Current/bin/Sdks/Microsoft.NET.Sdk.Razor/build/netstandard2.0/Microsoft.NET.Sdk.Razor.Component.targets(106,5): Error: rzc generate exited with code 129.
```

```
[fail]: OmniSharp.Stdio.Host
************ Response ************
{
"Request_seq": 6614,
"Command": "/v2/highlight",
"Running": true,
"Success": false,
"Message": "\"System.ArgumentOutOfRangeException: Specified argument was out of the range of valid values.\\nParameter name: character\\n at Microsoft.CodeAnalysis.Text.LinePosition..ctor (System.Int32 line, System.Int32 character) [0x00013] in <74e762f007514b0991a005183ec8dcb2>:0 \\n at OmniSharp.Roslyn.CSharp.Services.SemanticHighlight.SemanticHighlightService.Handle (OmniSharp.Models.SemanticHighlight.SemanticHighlightRequest request) [0x00146] in <845c3087cc7d4530b36a8584d73f1c1d>:0 \\n at OmniSharp.Endpoint.EndpointHandler`2[TRequest,TResponse].GetFirstNotEmptyResponseFromHandlers (OmniSharp.Endpoint.Exports.ExportHandler`2[TRequest,TResponse][] handlers, TRequest request) [0x00099] in <0b3dc7d6f0c8428682a86ac3f9663775>:0 \\n at OmniSharp.Endpoint.EndpointHandler`2[TRequest,TResponse].HandleRequestForLanguage (System.String language, TRequest request, OmniSharp.Protocol.RequestPacket packet) [0x00163] in <0b3dc7d6f0c8428682a86ac3f9663775>:0 \\n at OmniSharp.Endpoint.EndpointHandler`2[TRequest,TResponse].Process (OmniSharp.Protocol.RequestPacket packet, OmniSharp.Endpoint.LanguageModel model, Newtonsoft.Json.Linq.JToken requestObject) [0x0024b] in <0b3dc7d6f0c8428682a86ac3f9663775>:0 \\n at OmniSharp.Stdio.Host.HandleRequest (System.String json, Microsoft.Extensions.Logging.ILogger logger) [0x000e7] in <0ff274924a1842faabf855aebc686508>:0 \"",
"Body": null,
"Seq": 7478,
"Type": "response"
}
[fail]: OmniSharp.Stdio.Host
************ Response ************
{
"Request_seq": 6617,
"Command": "/v2/highlight",
"Running": true,
"Success": false,
"Message": "\"System.ArgumentOutOfRangeException: Specified argument was out of the range of valid values.\\nParameter name: character\\n at Microsoft.CodeAnalysis.Text.LinePosition..ctor (System.Int32 line, System.Int32 character) [0x00013] in <74e762f007514b0991a005183ec8dcb2>:0 \\n at OmniSharp.Roslyn.CSharp.Services.SemanticHighlight.SemanticHighlightService.Handle (OmniSharp.Models.SemanticHighlight.SemanticHighlightRequest request) [0x00146] in <845c3087cc7d4530b36a8584d73f1c1d>:0 \\n at OmniSharp.Endpoint.EndpointHandler`2[TRequest,TResponse].GetFirstNotEmptyResponseFromHandlers (OmniSharp.Endpoint.Exports.ExportHandler`2[TRequest,TResponse][] handlers, TRequest request) [0x00099] in <0b3dc7d6f0c8428682a86ac3f9663775>:0 \\n at OmniSharp.Endpoint.EndpointHandler`2[TRequest,TResponse].HandleRequestForLanguage (System.String language, TRequest request, OmniSharp.Protocol.RequestPacket packet) [0x00163] in <0b3dc7d6f0c8428682a86ac3f9663775>:0 \\n at OmniSharp.Endpoint.EndpointHandler`2[TRequest,TResponse].Process (OmniSharp.Protocol.RequestPacket packet, OmniSharp.Endpoint.LanguageModel model, Newtonsoft.Json.Linq.JToken requestObject) [0x0024b] in <0b3dc7d6f0c8428682a86ac3f9663775>:0 \\n at OmniSharp.Stdio.Host.HandleRequest (System.String json, Microsoft.Extensions.Logging.ILogger logger) [0x000e7] in <0ff274924a1842faabf855aebc686508>:0 \"",
"Body": null,
"Seq": 7484,
"Type": "response"
}
```

## Actual behavior
Omnisharp fails to load the project. Causing intellisense to fail